As the end-stage of prostate cancer, metastatic castration-resistant prostate cancer(mCRPC) complicates the disease and therefore challenges the doctors. In October 2018, an 87-year-old patient diagnosed with metastatic prostate cancer was admitted to Shanghai General Hospital for evaluation and treatment. Poor basic health condition plus severe side effect resulted in patient’s poor compliance with treatment and irregular follow-up. The patient progressed to mCRPC in September 2020, and was given enzalutamide as first-line therapy, after which the patient’s PSA level was under control with no side effect.