To the Editor.— Several malignant diseases have been observed in patients with the acquired immunodeficiency syndrome (AIDS) and its clinical precursors. Most of the tumors reported were Kaposi's sarcoma, and a smaller number of tumors reported were lymphomas. Carcinomas have also been reported. These observations support the possible role of T cells in the control of malignant cell development.1 The following case report deals with a malignant melanoma that developed in a patient with AIDS-related complex. Report of a Case.— A 35-year-old man was a drug abuser (morphine and, later, heroin) from the ages of 18 to 25 years and had suffered a relapse three years ago. In 1970, hepatitis B developed; in December 1985, anti-human T-cell lymphotropic virus type III antibodies were detected for the first time. Serum electrophoresis and T-cell count were normal, but the ratio of T helper cells to T suppressor cells was low (0.64).