Seventeen patients who had cutaneous complications following pentazocine injections are presented. The mean age was 50 years; total daily pentazocine dose ranged from 60 to 2,400 mg; evidence of psychiatric illness was present in 94%, and previous drug or alcohol abuse was noted in 65%. Fifty-three percent of our series of patients had a medical or paramedical background. Eighteen percent had diabetes mellitus, and 65% had a personal or family history (or both) of diabetes. A hypothesis is presented for this association. Characteristic histologic findings included fibrosis of the dermis and panniculus, with vascular alterations, fat necrosis with granulomatous inflammation, and vascular thrombosis with occasional endarteritis. We emphasize that medical and paramedical personnel and patients with a personal or family history of diabetes should be added to the group of patients considered to be at special risk for cutaneous complications of pentazocine injections.