diff --git a/.changeset/heavy-yaks-mate.md b/.changeset/heavy-yaks-mate.md
new file mode 100644
index 00000000..3094f31d
--- /dev/null
+++ b/.changeset/heavy-yaks-mate.md
@@ -0,0 +1,5 @@
+---
+"@openai/agents-openai": patch
+---
+
+Handle function call messages with empty content in Chat Completions
diff --git a/packages/agents-openai/src/openaiChatCompletionsModel.ts b/packages/agents-openai/src/openaiChatCompletionsModel.ts
index 885eadaa..e4829f84 100644
--- a/packages/agents-openai/src/openaiChatCompletionsModel.ts
+++ b/packages/agents-openai/src/openaiChatCompletionsModel.ts
@@ -67,7 +67,13 @@ export class OpenAIChatCompletionsModel implements Model {
     const output: protocol.OutputModelItem[] = [];
     if (response.choices && response.choices[0]) {
       const message = response.choices[0].message;
-      if (message.content !== undefined && message.content !== null) {
+      
+      if (
+        message.content !== undefined &&
+        message.content !== null &&
+        // Azure OpenAI returns empty string instead of null for tool calls, causing parser rejection
+        !(message.tool_calls && message.content === '')
+      ) {
         const { content, ...rest } = message;
         output.push({
           id: response.id,