The clinical course of endophthalmitis, presumably due to Candida albicans, in nine eyes of heroin addicts is described. In six of the seven eyes in which pars plana vitrectomy was performed the diagnosis was confirmed by the cultivation of Candida albicans from the rinsing fluid. Both purely intraocular treatment and a combination of local and systemic antimycotic therapy caused the intraocular infection to disappear. In this small group of patients the results were most favourable when treatment was started early.