There are several neuromuscular complications in the intravenous heroin addict (IHA). Someone may be due to direct toxic effect of the substance, but other ones may be associated to abuser's typical diseases (i.e. HIV infection). We present a 27 year-old IHA patient, HIV positive, that develop acute rhabdomyolisis with severe neuromuscular involvement, and consistent clinical and electrodiagnostic features of lumbosacral plexus neuropathy, forteen hours after an heroin inyection. Thirty months later, the patient is severely disabled, but her initial painfull and paretic picture have improved. The association of rhabdomyolisis-lumbosacral plexopathy (RLPS) is ocasionally reported. It has been proposed that RLSP is etiologically related to mecanic, toxic and immunologic factors.