Primary malignant melanoma of the esophagus（PMME）is extraordinarily rare with a high degree of malignancy and poor prognosis, and a standard therapy remains to be established. The anti-PD-1 antibody nivolumab is a promising agent for various cancers. To our knowledge, this is the first case report of PMME where a complete response was achieved using nivolumab. We report an 80-year-old woman who was diagnosed with PMME with bone metastasis and lymph node metastases. Although dacarbazine combined chemotherapy was performed and continued for six cycles, the primary tumor progressed and liver metastases appeared. The patient then received nivolumab monotherapy. After three cycles, nivolumab monotherapy for PMME resulted in a complete response as shown by positron emission tomography, computed tomography, and esophagogastroduodenoscopy. In our case, nivolumab exerted a curative effect on PMME, thus suggesting that nivolumab can be effective in the treatment of this rare disease
