diff --git a/doc/source/whatsnew/v1.4.0.rst b/doc/source/whatsnew/v1.4.0.rst
index caf3a4281561f..044361de218df 100644
--- a/doc/source/whatsnew/v1.4.0.rst
+++ b/doc/source/whatsnew/v1.4.0.rst
@@ -769,6 +769,7 @@ Period
 - Bug in adding a :class:`Period` object to a ``np.timedelta64`` object incorrectly raising ``TypeError`` (:issue:`44182`)
 - Bug in :meth:`PeriodIndex.to_timestamp` when the index has ``freq="B"`` inferring ``freq="D"`` for its result instead of ``freq="B"`` (:issue:`44105`)
 - Bug in :class:`Period` constructor incorrectly allowing ``np.timedelta64("NaT")`` (:issue:`44507`)
+- Bug in :meth:`PeriodIndex.to_timestamp` giving incorrect values for indexes with non-contiguous data (:issue:`44100`)
 -
 
 Plotting
diff --git a/pandas/_libs/tslibs/period.pyx b/pandas/_libs/tslibs/period.pyx
index 67696f9740ea1..1df1c9a947e8d 100644
--- a/pandas/_libs/tslibs/period.pyx
+++ b/pandas/_libs/tslibs/period.pyx
@@ -1088,6 +1088,7 @@ def period_asfreq_arr(ndarray[int64_t] arr, int freq1, int freq2, bint end):
     """
     cdef:
         Py_ssize_t n = len(arr)
+        Py_ssize_t increment = arr.strides[0] // 8
         ndarray[int64_t] result = np.empty(n, dtype=np.int64)
 
     _period_asfreq(
@@ -1097,6 +1098,7 @@ def period_asfreq_arr(ndarray[int64_t] arr, int freq1, int freq2, bint end):
         freq1,
         freq2,
         end,
+        increment,
     )
     return result
 
@@ -1110,6 +1112,7 @@ cdef void _period_asfreq(
     int freq1,
     int freq2,
     bint end,
+    Py_ssize_t increment=1,
 ):
     """See period_asfreq.__doc__"""
     cdef:
@@ -1127,7 +1130,7 @@ cdef void _period_asfreq(
     get_asfreq_info(freq1, freq2, end, &af_info)
 
     for i in range(length):
-        val = ordinals[i]
+        val = ordinals[i * increment]
         if val != NPY_NAT:
             val = func(val, &af_info)
         out[i] = val
diff --git a/pandas/tests/indexes/period/methods/test_to_timestamp.py b/pandas/tests/indexes/period/methods/test_to_timestamp.py
index c2328872aee1b..164ed3ec43996 100644
--- a/pandas/tests/indexes/period/methods/test_to_timestamp.py
+++ b/pandas/tests/indexes/period/methods/test_to_timestamp.py
@@ -16,6 +16,36 @@
 
 
 class TestToTimestamp:
+    def test_to_timestamp_non_contiguous(self):
+        # GH#44100
+        dti = date_range("2021-10-18", periods=9, freq="B")
+        pi = dti.to_period()
+
+        result = pi[::2].to_timestamp()
+        expected = dti[::2]
+        tm.assert_index_equal(result, expected)
+
+        result = pi._data[::2].to_timestamp()
+        expected = dti._data[::2]
+        # TODO: can we get the freq to round-trip?
+        tm.assert_datetime_array_equal(result, expected, check_freq=False)
+
+        result = pi[::-1].to_timestamp()
+        expected = dti[::-1]
+        tm.assert_index_equal(result, expected)
+
+        result = pi._data[::-1].to_timestamp()
+        expected = dti._data[::-1]
+        tm.assert_datetime_array_equal(result, expected, check_freq=False)
+
+        result = pi[::2][::-1].to_timestamp()
+        expected = dti[::2][::-1]
+        tm.assert_index_equal(result, expected)
+
+        result = pi._data[::2][::-1].to_timestamp()
+        expected = dti._data[::2][::-1]
+        tm.assert_datetime_array_equal(result, expected, check_freq=False)
+
     def test_to_timestamp_freq(self):
         idx = period_range("2017", periods=12, freq="A-DEC")
         result = idx.to_timestamp()