Long-term intravenous heroin abusers have problems of vascular access. After the accessible sites are sclerosed, the neck, axillae and groins are then used frequently. We report on 3 heroin abusers who presented with localized gangrene of the genitalia after injection into the femoral vessels. We postulate that the pathophysiology of this entity is related to arterial embolization of particulate matter into the microcirculation of the genitalia, which causes arterial thrombosis leading to localized gangrene. Of the 3 patients 2 were treated with local excision, débridement and primary closure. A fourth addict who injected heroin directly into the scrotum and perineum, presented with Fournier's gangrene, a completely different, more lethal entity.