diff --git a/litellm/llms/prompt_templates/factory.py b/litellm/llms/prompt_templates/factory.py
index eba8e27ea39..8ab83d3d35b 100644
--- a/litellm/llms/prompt_templates/factory.py
+++ b/litellm/llms/prompt_templates/factory.py
@@ -705,7 +705,7 @@ def anthropic_messages_pt_xml(messages: list):
         if assistant_content:
             new_messages.append({"role": "assistant", "content": assistant_content})
 
-    if new_messages[0]["role"] != "user":
+    if not new_messages or new_messages[0]["role"] != "user":
         if litellm.modify_params:
             new_messages.insert(
                 0, {"role": "user", "content": [{"type": "text", "text": "."}]}
@@ -884,7 +884,7 @@ def anthropic_messages_pt(messages: list):
         if assistant_content:
             new_messages.append({"role": "assistant", "content": assistant_content})
 
-    if new_messages[0]["role"] != "user":
+    if not new_messages or new_messages[0]["role"] != "user":
         if litellm.modify_params:
             new_messages.insert(
                 0, {"role": "user", "content": [{"type": "text", "text": "."}]}
diff --git a/litellm/tests/test_prompt_factory.py b/litellm/tests/test_prompt_factory.py
index 9116ecc9503..8bf66e84d94 100644
--- a/litellm/tests/test_prompt_factory.py
+++ b/litellm/tests/test_prompt_factory.py
@@ -2,13 +2,16 @@
 #    This tests if prompts are being correctly formatted
 import sys
 import os
+import pytest
 
 sys.path.insert(0, os.path.abspath("../.."))
 
 # from litellm.llms.prompt_templates.factory import prompt_factory
+import litellm
 from litellm import completion
 from litellm.llms.prompt_templates.factory import (
     anthropic_pt,
+    anthropic_messages_pt,
     claude_2_1_pt,
     llama_2_chat_pt,
 )
@@ -94,4 +97,18 @@ def test_anthropic_pt_formatting():
     assert anthropic_pt(messages) == expected_prompt
 
 
+def test_anthropic_messages_pt():
+    # Test case: No messages (filtered system messages only)
+    litellm.modify_params = True
+    messages = []
+    expected_messages = [{"role": "user", "content": [{"type": "text", "text": "."}]}]
+    assert anthropic_messages_pt(messages) == expected_messages
+
+    # Test case: No messages (filtered system messages only) when modify_params is False should raise error
+    litellm.modify_params = False
+    messages = []
+    with pytest.raises(Exception) as err:
+        anthropic_messages_pt(messages)
+    assert("Invalid first message." in str(err.value))
+
 # codellama_prompt_format()