We report four cases of malignant melanoma of the esophagus treated at the National Cancer Center Hospital in Tokyo over a period of 28 years. There were three men and one woman. One patient had been diagnosed as having Werner's syndrome. The three male patients smoked and were alcohol drinkers. The chief complaint was dysphagia--three patients--and pain on swallowing--one patient. All the tumors were polypoid, and three were large at the time of initial diagnosis. Histological diagnoses were made by examining endoscopic biopsy specimens, and confirmed with resected specimens in three cases. Esophagectomy was performed in three patients, the other receiving radiotherapy. Three patients died of recurrent disease in a rather short period of time, as in many reported cases. The mean survival for the three patients was eight months. The fourth, who had a superficial polypoid lesion and received esophagectomy and adjuvant chemotherapy, lived for 29 months. The combination of early detection and extended radical surgery followed by adjuvant chemotherapy may offer a better prognosis than in the past.