diff --git a/litellm/litellm_core_utils/prompt_templates/factory.py b/litellm/litellm_core_utils/prompt_templates/factory.py
index 795fb36961e..84b89a52ea4 100644
--- a/litellm/litellm_core_utils/prompt_templates/factory.py
+++ b/litellm/litellm_core_utils/prompt_templates/factory.py
@@ -2393,6 +2393,28 @@ def anthropic_messages_pt(
                                     "url": image_url_value["url"],
                                     "format": image_url_value.get("format"),
                                 }
+                            url_str = (
+                                image_url_value.get("url") if isinstance(image_url_value, dict) else image_url_value
+                            )
+                            if isinstance(url_str, str) and _is_anthropic_document_data_uri(url_str):  # pyright: ignore[reportUnnecessaryIsInstance]  # malformed payloads can carry a non-str url
+                                image_chunk = convert_to_anthropic_image_obj(
+                                    openai_image_url=url_str,
+                                    format=None,
+                                )
+                                _document_content_element = AnthropicMessagesDocumentParam(
+                                    type="document",
+                                    source=AnthropicContentParamSource(
+                                        type="base64",
+                                        media_type=image_chunk["media_type"],
+                                        data=image_chunk["data"],
+                                    ),
+                                )
+                                add_cache_control_to_content(
+                                    anthropic_content_element=_document_content_element,
+                                    original_content_element=m,  # pyright: ignore[reportArgumentType]  # cache_control lives on the block
+                                )
+                                user_content.append(_document_content_element)
+                                continue
                             # Bedrock invoke models have format: invoke/...
                             # Vertex AI Anthropic also doesn't support URL sources for images
                             is_bedrock_invoke = model.lower().startswith("invoke/")
diff --git a/tests/test_litellm/litellm_core_utils/prompt_templates/test_litellm_core_utils_prompt_templates_factory.py b/tests/test_litellm/litellm_core_utils/prompt_templates/test_litellm_core_utils_prompt_templates_factory.py
index 72d26f31c60..5ed81232c45 100644
--- a/tests/test_litellm/litellm_core_utils/prompt_templates/test_litellm_core_utils_prompt_templates_factory.py
+++ b/tests/test_litellm/litellm_core_utils/prompt_templates/test_litellm_core_utils_prompt_templates_factory.py
@@ -2164,6 +2164,34 @@ def test_anthropic_messages_pt_file_block_without_cache_control():
     assert "cache_control" not in file_block
 
 
+def test_anthropic_messages_pt_maps_pdf_data_uri_to_document_block():
+    messages = [
+        {
+            "role": "user",
+            "content": [
+                {
+                    "type": "image_url",
+                    "image_url": {"url": "data:application/pdf;base64,AAAA"},
+                }
+            ],
+        }
+    ]
+
+    result = anthropic_messages_pt(
+        messages=messages,
+        model="claude-sonnet-4-5",
+        llm_provider="anthropic",
+    )
+
+    document = result[0]["content"][0]
+    assert document["type"] == "document"
+    assert document["source"] == {
+        "type": "base64",
+        "media_type": "application/pdf",
+        "data": "AAAA",
+    }
+
+
 # ── _convert_to_bedrock_tool_call_invoke tests ──