Melanoma is an especially important malignant disease for surgeons to know about, since it can be cured with surgical treatment if diagnosed at an early stage. In the American College of Surgeons Melanoma Survey of 4,545 melanoma patients diagnosed during 1980, the typical melanoma was relatively thin (less than 1.5 millimeters), not ulcerated (except in 9 per cent) and did not invade into the reticular dermis or beyond (level IV or V). The melanomas were most commonly located on the trunk in men and on the lower extremities in women. Eighty-eight per cent of the patients had no clinical evidence of metastases to regional nodes or to distant sites at the time of initial diagnosis. Only a small proportion (1 per cent) of patients in the survey were black and in most of these patients, their melanoma were located on the feet or hands. The treatment of melanoma was surgical in 92.5 per cent of the patients, with the majority of patients undergoing a wide excision of the melanoma as the initial form of treatment. Only one-fifth of the patients underwent elective regional node dissection for suspected micrometastases, and most of these patients had a tumor thickness exceeding 1.5 millimeters or a lesion invading to the reticular dermis (level III, IV or V). While the Breslow Microstaging Method is now recognized as the most important parameter that predicts the clinical course of the patient, this parameter was reported in only 45 per cent of the patients in the survey. The natural history of melanoma is changing, since the disease is increasing in frequency and becoming more curable. Surgical treatment should be tailored to the biologic aggressiveness of each individual patient's melanoma. This can be estimated by integrating such prognostic factors as the melanoma thickness, the presence or absence of ulceration, the level of invasion, the anatomic site and the gender of the patient.