Abstract The records of 154 patients with cutaneous malignant melanoma seen during a twenty-five year period at the University of California Medical Center were reviewed. Patients with all stages of disease, including those presenting with no identifiable primary lesion, were analyzed. All patients were white and the median age was forty-seven years. The sex distribution was approximately equal. A pre-existing nevus was found in 74 per cent of cases and the interval from onset of growth to treatment varied from one week to twenty years. Clinical evidence of metastases was present in 41 per cent of patients at first examination. The comparison of different modes of therapy demonstrated that long-term survival was not increased by prophylactic node dissection; 15 per cent of patients treated in this manner had histologically positive nodes. Treatment with chemotherapeutic agents, radiation therapy, or both, offered only short-term benefits and no cures. Most of the deaths from melanoma occurred within two years of the time of primary treatment. The overall five year survival rate was 49 per cent. The ten year survival rate was 33 per cent. Coexisting malignant neoplasms were found in 20 per cent of these patients, suggesting a lower resistance of the host to formation of tumors in patients with malignant melanoma. This statistically significant higher incidence of other malignant lesions compared to that of the general population points out the need for vigorous evaluation of symptoms arising after operation for melanoma.