A processing-in-memory (PIM) and a method of outputting an instruction using a PIM. The PIM includes an internal processor, a memory, and a register configured to store instruction meta information. The memory is configured to store a lookup table generated by predicting a future instruction. The external processor is configured to retrieve an instruction corresponding to the instruction meta information from the lookup table in response to a PIM application programming interface (API) call instruction including the instruction meta information. The instruction corresponding to the instruction meta information is output based on a retrieval result.