diff --git a/src/app/qgsdiagramproperties.cpp b/src/app/qgsdiagramproperties.cpp
index 5082518cda1e..e635b7650f85 100644
--- a/src/app/qgsdiagramproperties.cpp
+++ b/src/app/qgsdiagramproperties.cpp
@@ -165,6 +165,7 @@ QgsDiagramProperties::QgsDiagramProperties( QgsVectorLayer* layer, QWidget* pare
       mDiagramFont = settingList.at( 0 ).font;
       QSizeF size = settingList.at( 0 ).size;
       mBackgroundColorButton->setColor( settingList.at( 0 ).backgroundColor );
+      mTransparencySlider->setValue( settingList.at( 0 ).transparency * 100 / 256 );
       mDiagramPenColorButton->setColor( settingList.at( 0 ).penColor );
       mPenWidthSpinBox->setValue( settingList.at( 0 ).penWidth );
       mDiagramSizeSpinBox->setValue(( size.width() + size.height() ) / 2.0 );
@@ -281,7 +282,7 @@ QgsDiagramProperties::QgsDiagramProperties( QgsVectorLayer* layer, QWidget* pare
       else
       {
         QMessageBox::warning( this, tr( "Unknown diagram type." ),
-          tr( "The diagram type '%s' is unknown. A default type is selected for you." ).arg( diagramName ), QMessageBox::Ok );
+          tr( "The diagram type '%1' is unknown. A default type is selected for you." ).arg( diagramName ), QMessageBox::Ok );
         mDiagramTypeComboBox->setCurrentIndex( mDiagramTypeComboBox->findText( tr( "Pie chart" ) ) );
       }
     }
@@ -337,7 +338,6 @@ void QgsDiagramProperties::on_mDiagramTypeComboBox_currentIndexChanged( const QS
   }
 }
 
-
 void QgsDiagramProperties::on_mIncreaseSmallDiagramsCheckBox_stateChanged( int state )
 {
   if ( Qt::Checked == state )
@@ -352,6 +352,10 @@ void QgsDiagramProperties::on_mIncreaseSmallDiagramsCheckBox_stateChanged( int s
   }
 }
 
+void QgsDiagramProperties::on_mTransparencySlider_valueChanged( int value )
+{
+  mTransparencyLabel->setText( tr( "Transparency: %1%" ).arg( value ) );
+}
 
 void QgsDiagramProperties::on_mAddCategoryPushButton_clicked()
 {
@@ -527,7 +531,13 @@ void QgsDiagramProperties::apply()
     }
 
     ds.backgroundColor = mBackgroundColorButton->color();
+    ds.transparency = mTransparencySlider->value() * 255 / 100;
+    foreach( QColor col, ds.categoryColors )
+    {
+      col.setAlpha( 255 - ds.transparency );
+    }
     ds.penColor = mDiagramPenColorButton->color();
+    ds.penColor.setAlpha( 255 - ds.transparency );
     ds.penWidth = mPenWidthSpinBox->value();
     if ( mVisibilityGroupBox->isChecked() )
     {
diff --git a/src/app/qgsdiagramproperties.h b/src/app/qgsdiagramproperties.h
index 490073c85912..b27419a42e13 100644
--- a/src/app/qgsdiagramproperties.h
+++ b/src/app/qgsdiagramproperties.h
@@ -36,6 +36,7 @@ class QgsDiagramProperties : public QWidget, private Ui::QgsDiagramPropertiesBas
     void apply();
     void on_mDiagramTypeComboBox_currentIndexChanged( const QString& itemtext );
     void on_mIncreaseSmallDiagramsCheckBox_stateChanged( int state );
+    void on_mTransparencySlider_valueChanged( int value );
     void on_mAddCategoryPushButton_clicked();
     void on_mBackgroundColorButton_clicked();
     void on_mFindMaximumValueButton_clicked();
diff --git a/src/core/diagram/qgspiediagram.cpp b/src/core/diagram/qgspiediagram.cpp
index efcd0c8f12bf..2097fc2496f1 100644
--- a/src/core/diagram/qgspiediagram.cpp
+++ b/src/core/diagram/qgspiediagram.cpp
@@ -119,7 +119,9 @@ void QgsPieDiagram::renderDiagram( const QgsAttributeMap& att, QgsRenderContext&
   for ( ; valIt != values.constEnd(); ++valIt, ++colIt )
   {
     currentAngle =  *valIt / valSum * 360 * 16;
-    mCategoryBrush.setColor( *colIt );
+    QColor col = *colIt;
+    col.setAlpha( 255 - s.transparency );
+    mCategoryBrush.setColor( col );
     p->setBrush( mCategoryBrush );
     p->drawPie( baseX, baseY, w, h, totalAngle, currentAngle );
     totalAngle += currentAngle;
diff --git a/src/core/qgsdiagramrendererv2.h b/src/core/qgsdiagramrendererv2.h
index 03114e6fe633..f191173766f7 100644
--- a/src/core/qgsdiagramrendererv2.h
+++ b/src/core/qgsdiagramrendererv2.h
@@ -124,6 +124,7 @@ struct CORE_EXPORT QgsDiagramSettings
   LabelPlacementMethod labelPlacementMethod;
   DiagramOrientation diagramOrientation;
   double barWidth;
+  int transparency; // 0 - 100
   bool scaleByArea;
 
   //scale range (-1 if no lower / upper bound )
diff --git a/src/ui/qgsdiagrampropertiesbase.ui b/src/ui/qgsdiagrampropertiesbase.ui
index 44ac00cfa5e3..5765d927aa5c 100644
--- a/src/ui/qgsdiagrampropertiesbase.ui
+++ b/src/ui/qgsdiagrampropertiesbase.ui
@@ -117,7 +117,7 @@
           <item>
            <widget class="QTabWidget" name="mDiagramPropertiesTabWidget">
             <property name="currentIndex">
-             <number>2</number>
+             <number>0</number>
             </property>
             <widget class="QWidget" name="tab">
              <attribute name="title">
@@ -126,40 +126,77 @@
              <layout class="QGridLayout" name="gridLayout_8">
               <item row="0" column="0" rowspan="2">
                <layout class="QGridLayout" name="gridLayout">
-                <item row="2" column="1">
+                <item row="3" column="1">
                  <widget class="QLabel" name="mBackgroundColorLabel">
                   <property name="text">
                    <string>Background color</string>
                   </property>
                  </widget>
                 </item>
-                <item row="3" column="1">
+                <item row="4" column="1">
                  <widget class="QLabel" name="mPenColorLabel">
                   <property name="text">
                    <string>Line color</string>
                   </property>
                  </widget>
                 </item>
-                <item row="3" column="2">
-                 <widget class="QgsColorButton" name="mDiagramPenColorButton">
+                <item row="5" column="1">
+                 <widget class="QLabel" name="mPenWidthLabel">
+                  <property name="text">
+                   <string>Line width</string>
+                  </property>
+                 </widget>
+                </item>
+                <item row="6" column="1">
+                 <widget class="QPushButton" name="mDiagramFontButton">
                   <property name="sizePolicy">
-                   <sizepolicy hsizetype="Minimum" vsizetype="Minimum">
+                   <sizepolicy hsizetype="Fixed" vsizetype="Fixed">
                     <horstretch>0</horstretch>
                     <verstretch>0</verstretch>
                    </sizepolicy>
                   </property>
+                  <property name="text">
+                   <string>Font...</string>
+                  </property>
+                 </widget>
+                </item>
+                <item row="1" column="1">
+                 <widget class="QLabel" name="mBarWidthLabel">
+                  <property name="text">
+                   <string>Bar width</string>
+                  </property>
+                 </widget>
+                </item>
+                <item row="2" column="1">
+                 <widget class="QLabel" name="mTransparencyLabel">
                   <property name="minimumSize">
                    <size>
-                    <width>25</width>
+                    <width>130</width>
                     <height>0</height>
                    </size>
                   </property>
                   <property name="text">
-                   <string/>
+                   <string>Transparency 0%</string>
                   </property>
                  </widget>
                 </item>
-                <item row="2" column="2">
+                <item row="2" column="2" colspan="2">
+                 <widget class="QSlider" name="mTransparencySlider">
+                  <property name="minimumSize">
+                   <size>
+                    <width>300</width>
+                    <height>0</height>
+                   </size>
+                  </property>
+                  <property name="maximum">
+                   <number>100</number>
+                  </property>
+                  <property name="orientation">
+                   <enum>Qt::Horizontal</enum>
+                  </property>
+                 </widget>
+                </item>
+                <item row="3" column="2">
                  <widget class="QgsColorButton" name="mBackgroundColorButton">
                   <property name="sizePolicy">
                    <sizepolicy hsizetype="Minimum" vsizetype="Minimum">
@@ -178,43 +215,35 @@
                   </property>
                  </widget>
                 </item>
-                <item row="4" column="1">
-                 <widget class="QLabel" name="mPenWidthLabel">
-                  <property name="text">
-                   <string>Line width</string>
-                  </property>
-                 </widget>
+                <item row="1" column="2">
+                 <widget class="QDoubleSpinBox" name="mBarWidthSpinBox"/>
                 </item>
                 <item row="4" column="2">
-                 <widget class="QDoubleSpinBox" name="mPenWidthSpinBox">
-                  <property name="decimals">
-                   <number>5</number>
-                  </property>
-                  <property name="maximum">
-                   <double>99999.990000000005239</double>
-                  </property>
-                 </widget>
-                </item>
-                <item row="5" column="1">
-                 <widget class="QPushButton" name="mDiagramFontButton">
+                 <widget class="QgsColorButton" name="mDiagramPenColorButton">
                   <property name="sizePolicy">
-                   <sizepolicy hsizetype="Fixed" vsizetype="Fixed">
+                   <sizepolicy hsizetype="Minimum" vsizetype="Minimum">
                     <horstretch>0</horstretch>
                     <verstretch>0</verstretch>
                    </sizepolicy>
                   </property>
+                  <property name="minimumSize">
+                   <size>
+                    <width>25</width>
+                    <height>0</height>
+                   </size>
+                  </property>
                   <property name="text">
-                   <string>Font...</string>
+                   <string/>
                   </property>
                  </widget>
                 </item>
-                <item row="1" column="2">
-                 <widget class="QDoubleSpinBox" name="mBarWidthSpinBox"/>
-                </item>
-                <item row="1" column="1">
-                 <widget class="QLabel" name="mBarWidthLabel">
-                  <property name="text">
-                   <string>Bar width</string>
+                <item row="5" column="2">
+                 <widget class="QDoubleSpinBox" name="mPenWidthSpinBox">
+                  <property name="decimals">
+                   <number>5</number>
+                  </property>
+                  <property name="maximum">
+                   <double>99999.990000000005239</double>
                   </property>
                  </widget>
                 </item>