diff --git a/haystack/components/preprocessors/nltk_document_splitter.py b/haystack/components/preprocessors/nltk_document_splitter.py
index d6f947ebfc..eb242d9013 100644
--- a/haystack/components/preprocessors/nltk_document_splitter.py
+++ b/haystack/components/preprocessors/nltk_document_splitter.py
@@ -2,6 +2,7 @@
 #
 # SPDX-License-Identifier: Apache-2.0
 
+import warnings
 from copy import deepcopy
 from typing import Any, Callable, Dict, List, Literal, Optional, Tuple
 
@@ -52,6 +53,13 @@ def __init__(  # pylint: disable=too-many-positional-arguments
             representing the chunks after splitting.
         """
 
+        warnings.warn(
+            "The NLTKDocumentSplitter is deprecated and will be removed in the next release. "
+            "See DocumentSplitter which now supports the functionalities of the NLTKDocumentSplitter, i.e.: "
+            "using NLTK to detect sentence boundaries.",
+            DeprecationWarning,
+        )
+
         super(NLTKDocumentSplitter, self).__init__(
             split_by=split_by,
             split_length=split_length,
diff --git a/releasenotes/notes/deprecating-NLTKDocumentSplitter-e9a621e025e9a49f.yaml b/releasenotes/notes/deprecating-NLTKDocumentSplitter-e9a621e025e9a49f.yaml
new file mode 100644
index 0000000000..e0331a00af
--- /dev/null
+++ b/releasenotes/notes/deprecating-NLTKDocumentSplitter-e9a621e025e9a49f.yaml
@@ -0,0 +1,4 @@
+---
+deprecations:
+  - |
+    The NLTKDocumentSplitter will deprecated and will be removed in the next release. The DocumentSplitter will instead support the functionality of the NLTKDocumentSplitter.