diff --git a/langchain/llms/base.py b/langchain/llms/base.py
index 9fbf983e..2e92c15d 100644
--- a/langchain/llms/base.py
+++ b/langchain/llms/base.py
@@ -287,6 +287,12 @@ class BaseLLM(BaseLanguageModel, ABC):
         self, prompt: str, stop: Optional[List[str]] = None, callbacks: Callbacks = None
     ) -> str:
         """Check Cache and run the LLM on the given prompt and input."""
+        if not isinstance(prompt, str):
+            raise ValueError(
+                "Argument `prompt` is expected to be a string. Instead found "
+                f"{type(prompt)}. If you want to run the LLM on multiple prompts, use "
+                "`generate` instead."
+            )
         return (
             self.generate([prompt], stop=stop, callbacks=callbacks)
             .generations[0][0]