diff --git a/litellm/llms/bedrock/chat/converse_transformation.py b/litellm/llms/bedrock/chat/converse_transformation.py
index fd8c0d75473..cb26a22edfa 100644
--- a/litellm/llms/bedrock/chat/converse_transformation.py
+++ b/litellm/llms/bedrock/chat/converse_transformation.py
@@ -55,6 +55,7 @@ from litellm.types.utils import (
 )
 from litellm.utils import (
     add_dummy_tool,
+    any_assistant_message_has_thinking_blocks,
     has_tool_call_blocks,
     last_assistant_with_tool_calls_has_no_thinking_blocks,
     supports_reasoning,
@@ -1077,11 +1078,15 @@ class AmazonConverseConfig(BaseConfig):
 
         # Drop thinking param if thinking is enabled but thinking_blocks are missing
         # This prevents the error: "Expected thinking or redacted_thinking, but found tool_use"
+        #
+        # IMPORTANT: Only drop thinking if NO assistant messages have thinking_blocks.
+        # If any message has thinking_blocks, we must keep thinking enabled, otherwise
         # Related issues: https://github.com/BerriAI/litellm/issues/14194
         if (
             optional_params.get("thinking") is not None
             and messages is not None
             and last_assistant_with_tool_calls_has_no_thinking_blocks(messages)
+            and not any_assistant_message_has_thinking_blocks(messages)
         ):
             if litellm.modify_params:
                 optional_params.pop("thinking", None)