To the Editor.— A number of medical complications of drug addiction have been described. 1,2 However, acute intravascular hemolysis presumably secondary to the substance (s) used to dilute the heroin has not been reported to our knowledge. Report of a Case.— A 24-year-old Negro had injected heroin into himself four hours prior to admission to Harbor General Hospital. At another hospital, where he was in a comatose state with pinpoint pupils, he had been given 15 mg of nalorphine, 5% dextrose in water, and oxygen. The patient was still comatose upon arrival. He had contusions about his face and multiple injection punctures on the right antecubital and forearm areas. His blood pressure was 90/70 mm Hg; pulse rate, 120 beats per minute; temperature per rectum, 38 C (100.4 F); and respirations 24 per minute. Physical examination revealed equal pupils with a diameter of 2 mm and normal fundi. There were