diff --git a/spec2vec/SpectrumDocument.py b/spec2vec/SpectrumDocument.py
index 70c8925..6669137 100644
--- a/spec2vec/SpectrumDocument.py
+++ b/spec2vec/SpectrumDocument.py
@@ -38,7 +38,8 @@ class SpectrumDocument(Document):
         [100.   150.   200.51]
         substance1
     """
-    def __init__(self, spectrum, n_decimals: int = 2):
+    def __init__(self, spectrum, n_decimals: int = 2,
+                 mz_from: float = 0.0, mz_to: float = 1000.0):
         """
 
         Parameters
@@ -49,16 +50,25 @@ def __init__(self, spectrum, n_decimals: int = 2):
             Peak positions are converted to strings with n_decimal decimals.
             The default is 2, which would convert a peak at 100.387 into the
             word "peak@100.39".
+        mz_from:
+            Set lower threshold for m/z values to take into account.
+            Default is 0.0.
+        mz_to:
+            Set upper threshold for m/z values to take into account.
+            Default is 1000.0.
         """
         self.n_decimals = n_decimals
+        self.mz_from = mz_from
+        self.mz_to = mz_to
         self.weights = None
         super().__init__(obj=spectrum)
         self._add_weights()
 
     def _make_words(self):
         """Create word from peaks (and losses)."""
+        mz_array_selected = self._obj.peaks.mz[(self._obj.peaks.mz >= self.mz_from) & (self._obj.peaks.mz <= self.mz_to)]
         format_string = "{}@{:." + "{}".format(self.n_decimals) + "f}"
-        peak_words = [format_string.format("peak", mz) for mz in self._obj.peaks.mz]
+        peak_words = [format_string.format("peak", mz) for mz in mz_array_selected]
         if self._obj.losses is not None:
             loss_words = [format_string.format("loss", mz) for mz in self._obj.losses.mz]
         else:
diff --git a/tests/test_spectrum_document.py b/tests/test_spectrum_document.py
index 67624cd..80eaed5 100644
--- a/tests/test_spectrum_document.py
+++ b/tests/test_spectrum_document.py
@@ -54,6 +54,22 @@ def test_spectrum_document_init_default_with_losses():
     assert next(spectrum_document) == "peak@10.00"
 
 
+def test_spectrum_document_init_default_peaks_outside_mz_range():
+    """Use default n_decimal and test if peaks outside mz_range are excluded."""
+    mz = numpy.array([310, 320, 330, 540], dtype="float")
+    intensities = numpy.array([1, 0.01, 0.1, 1], dtype="float")
+    metadata = dict(precursor_mz=100.0)
+    spectrum_in = Spectrum(mz=mz, intensities=intensities, metadata=metadata)
+    spectrum_document = SpectrumDocument(spectrum_in, mz_to=500.0)
+
+    assert spectrum_document.n_decimals == 2, "Expected different default for n_decimals"
+    assert len(spectrum_document) == 3
+    assert spectrum_document.words == [
+        "peak@310.00", "peak@320.00", "peak@330.00"
+    ]
+    assert next(spectrum_document) == "peak@310.00"
+
+
 def test_spectrum_document_init_n_decimals_1():
     """Use n_decimal=1 and add losses."""
     mz = numpy.array([10, 20, 30, 40], dtype="float")