In a personal series of 559 patients with black lesions on the skin, only 2.1% had malignant melanomas; about 98% were not melanomatous. Of 31 instances in which melanoma was suspected, the diagnosis was proven by histopathologic examination in only 12 (38.7%). Since melanoma surgery is mutilating, biopsy studies would be helpful if they were not damaging to the patient. Of the 193 surgically treated localized malignant melanomas reported to the California Tumor Registry from 1950 to 1954, incomplete excision was performed in 115 cases. Definitive surgery was done later in 90 of these cases— as much as one week later in 73. A comparison of the survival rates of the 115 patients on whom biopsies were done with those of the 55 patients on whom definitive surgery was performed immediately showed no deleterious effect from the delayed surgery.