diff --git a/src/starfile/functions.py b/src/starfile/functions.py
index 792f666..4ba0669 100644
--- a/src/starfile/functions.py
+++ b/src/starfile/functions.py
@@ -55,6 +55,7 @@ def write(
     na_rep: str = '<NA>',
     quote_character: str = '"',
     quote_all_strings: bool = False,
+    include_field_numbers: bool = True,
     **kwargs
 ):
     """Write data to disk in the STAR format.
@@ -72,6 +73,11 @@ def write(
         Separator between values, will be passed to pandas.
     na_rep: str
         Representation of null values, will be passed to pandas.
+    include_field_numbers: bool
+        Whether field numbers should be included after field names in the ouput file. 
+        Default is True which includes field numbers (i.e. `_rlnImageName #1`) and is 
+        compatible with RELION and Python STOPGAP. False excludes field numbers (i.e. 
+        `_motl_idx`) and is compatible with legacy/MATLAB STOPGAP.
     """
     StarWriter(
         data,
@@ -81,6 +87,7 @@ def write(
         separator=sep,
         quote_character=quote_character,
         quote_all_strings=quote_all_strings,
+        include_field_numbers=include_field_numbers,
     ).write()
 
 
diff --git a/src/starfile/writer.py b/src/starfile/writer.py
index be8d784..0418857 100644
--- a/src/starfile/writer.py
+++ b/src/starfile/writer.py
@@ -27,6 +27,7 @@ def __init__(
         na_rep: str = '<NA>',
         quote_character: str = '"',
         quote_all_strings: bool = False,
+        include_field_numbers: bool = True,
     ):
         # coerce data
         self.data_blocks = self.coerce_data_blocks(data_blocks)
@@ -40,6 +41,7 @@ def __init__(
         self.na_rep = na_rep
         self.quote_character = quote_character
         self.quote_all_strings = quote_all_strings
+        self.include_field_numbers = include_field_numbers
         self.buffer = TextBuffer()
         self.backup_if_file_exists()
 
@@ -93,7 +95,8 @@ def data_block_generator(self) -> Generator[str, None, None]:
                     separator=self.sep,
                     na_rep=self.na_rep,
                     quote_character=self.quote_character,
-                    quote_all_strings=self.quote_all_strings
+                    quote_all_strings=self.quote_all_strings,
+                    include_field_numbers=self.include_field_numbers,
                 ):
                     yield line
 
@@ -163,7 +166,8 @@ def loop_block(
     separator: str = '\t',
     na_rep: str = '<NA>',
     quote_character: str = '"',
-    quote_all_strings: bool = False
+    quote_all_strings: bool = False,
+    include_field_numbers: bool = True,
 ) -> Generator[str, None, None]:
 
     # Header
@@ -171,7 +175,7 @@ def loop_block(
     yield ''
     yield 'loop_'
     for idx, column_name in enumerate(df.columns, 1):
-        yield f'_{column_name} #{idx}'
+        yield f'_{column_name} #{idx}' if include_field_numbers else f'_{column_name}'
 
     # Data
     for line in df.map(lambda x:
diff --git a/tests/test_writing.py b/tests/test_writing.py
index 8e0ee00..135e319 100644
--- a/tests/test_writing.py
+++ b/tests/test_writing.py
@@ -72,6 +72,24 @@ def test_can_write_non_zero_indexed_one_row_dataframe():
     assert (expected in output)
 
 
+@pytest.mark.parametrize("include_field_numbers, expected", 
+                         [
+                             (True, "_Brand #1\n_Price #2\n"),
+                             (False, "_Brand\n_Price\n"),
+                         ])
+def test_include_exclude_field_numbers(include_field_numbers, expected):
+    with TemporaryDirectory() as directory:
+        filename = join_path(directory, "test.star")
+        StarWriter(
+            test_df, 
+            filename, 
+            include_field_numbers=include_field_numbers
+        ).write()
+        with open(filename) as output_file:
+            output = output_file.read()
+    assert (expected in output)
+
+
 @pytest.mark.parametrize("quote_character, quote_all_strings, num_quotes", 
                          [('"', False, 6),
                           ('"', True, 8),