IntroductionNeuroendocrine prostate cancer is an aggressive histological subtype of prostate cancer with a poor prognosis. Neuroendocrine prostate cancer is traditionally treated with cisplatin‐based chemotherapy, similar to that used in treating small‐cell lung cancer. However, the therapeutic effectiveness of chemotherapy for neuroendocrine prostate cancer has been limited. This case report describes a response to triplet therapy using darolutamide, androgen deprivation therapy, and docetaxel, which was administered in a patient with mixed neuroendocrine prostate cancer.Case presentationA 77‐year‐old man was newly diagnosed with mixed neuroendocrine prostate cancer. Serum prostate‐specific antigen, neuron‐specific enolase, and progastrin‐releasing peptide levels were 62.2, 40.6, and 60.6 pg/mL, respectively. Multiple lymph node metastases were identified on a computed tomography scan, and bone scintigraphy revealed multiple bone metastases. The clinical stage was determined to be cT3bN1M1b. Ultimately, tumor size and serum markers decreased with triplet therapy.ConclusionWe demonstrated the first case in which triplet therapy had been effective in the treatment of neuroendocrine prostate cancer.