diff --git a/README.md b/README.md
index b9fb2407..7216cbd3 100644
--- a/README.md
+++ b/README.md
@@ -50,6 +50,8 @@ By default rails_best_practices will do parse codes in vendor, spec, test and fe
             --features                   include features files
         -x, --exclude PATTERNS           Don't analyze files matching a pattern
                                          (comma-separated regexp list)
+        -o, --only PATTERNS              analyze files only matching a pattern
+                                         (comma-separated regexp list)
         -g, --generate                   Generate configuration yaml
         -v, --version                    Show this version
         -h, --help                       Show this message
diff --git a/lib/rails_best_practices/analyzer.rb b/lib/rails_best_practices/analyzer.rb
index 6e2c3cd3..a028f73e 100644
--- a/lib/rails_best_practices/analyzer.rb
+++ b/lib/rails_best_practices/analyzer.rb
@@ -46,6 +46,7 @@ def generate
     # @param [Hash] options
     def analyze
       @options["exclude"] ||= []
+      @options["only"] ||= []
       @options["output-file"] ||= "rails_best_practices_output.html"
 
       Core::Runner.base_path = @path
@@ -98,6 +99,10 @@ def parse_files
         files = expand_dirs_to_files(@path)
         files = file_sort(files)
 
+        if @options["only"].present?
+          files = file_accept(files, @options["only"])
+        end
+
         # By default, tmp, vender, spec, test, features are ignored.
         ["vendor", "spec", "test", "features", "tmp"].each do |pattern|
           files = file_ignore(files, "#{pattern}/") unless @options[pattern]
@@ -157,6 +162,14 @@ def file_ignore files, pattern
       files.reject { |file| file.index(pattern) }
     end
 
+    # accept specific files.
+    #
+    # @param [Array] files
+    # @param [Regexp] patterns, files match any pattern will be accepted
+    def file_accept files, patterns
+      files.reject { |file| !patterns.any? { |pattern| file =~ pattern } }
+    end
+
     # output errors on terminal.
     def output_terminal_errors
       @runner.errors.each { |error| plain_output(error.to_s, 'red') }
diff --git a/lib/rails_best_practices/command.rb b/lib/rails_best_practices/command.rb
index 02b114ee..f7fbf9d9 100644
--- a/lib/rails_best_practices/command.rb
+++ b/lib/rails_best_practices/command.rb
@@ -19,6 +19,8 @@
 #        --features                   include features files
 #    -x, --exclude PATTERNS           don't analyze files matching a pattern
 #                                     (comma-separated regexp list)
+#    -o, --only PATTERNS              analyze files only matching a pattern
+#                                     (comma-separated regexp list)
 #    -g, --generate                   generate configuration yaml
 #    -v, --version                    show this version
 #    -h, --help                       show this message
@@ -94,12 +96,20 @@
 
   opts.on("-x", "--exclude PATTERNS", "Don't analyze files matching a pattern", "(comma-separated regexp list)") do |list|
     begin
-      options["exclude"] = list.split(/,/).map{|x| Regexp.new x}
+      options["exclude"] = list.split(",").map{|x| Regexp.new x}
     rescue RegexpError => e
       raise OptionParser::InvalidArgument, e.message
     end
   end
 
+  opts.on("-o", "--only PATTERNS", "Analyze files only matching a pattern", "(comma-separated regexp list)") do |list|
+    begin
+      options["only"] = list.split(",").map { |x| Regexp.new x }
+    rescue RegexpError => e
+      raise OptionParser::InvalidArgument e.message
+    end
+  end
+
   opts.on("-g", "--generate", "Generate configuration yaml") do
     options["generate"] = true
   end