diff --git a/src/phoenix/server/api/helpers/playground_clients.py b/src/phoenix/server/api/helpers/playground_clients.py
index 0b79147e4a..e7e84f6a6e 100644
--- a/src/phoenix/server/api/helpers/playground_clients.py
+++ b/src/phoenix/server/api/helpers/playground_clients.py
@@ -575,6 +575,8 @@ def __init__(
         super().__init__(model=model, api_key=api_key)
         self._attributes[LLM_PROVIDER] = OpenInferenceLLMProviderValues.AZURE.value
         self._attributes[LLM_SYSTEM] = OpenInferenceLLMSystemValues.OPENAI.value
+        if not (api_key := api_key or os.environ.get("AZURE_OPENAI_API_KEY")):
+            raise BadRequest("An Azure API key is required for Azure OpenAI models")
         if not (endpoint := model.endpoint or os.environ.get("AZURE_OPENAI_ENDPOINT")):
             raise BadRequest("An Azure endpoint is required for Azure OpenAI models")
         if not (api_version := model.api_version or os.environ.get("OPENAI_API_VERSION")):