OBJECTIVE Abuse of cocaine is associated with serious medical complications involving the heart, central nervous system, and gastrointestinal tract. Renal complications appear to be uncommon. We describe herein four patients with rhabdomyolysis and acute myoglobinuric renal failure temporally related to cocaine use. METHODS Acute cocaine intoxication was the most common presentation and rhabdomyolysis was an unexpected finding. Renal failure progressed rapidly in all patients, necessitating dialysis in two. The prognosis was good, and all patients survived. The mechanism of cocaine injury is unclear; possibilities include increased muscle activity, muscle compression, hyperthermia, and vasospasm with muscle ischemia. CONCLUSIONS Rhabdomyolysis with acute renal failure should be recognized as a possible complication of cocaine abuse.