A 50-year-old man suffered an MI with VFIB at work, and efforts at resuscitation were initiated immediately. Ninety minutes of CPR and 14 cardioversion were given by trained personnel before VFIB converted to sinus rhythm. Reversible myoglobinuric renal failure ensued, requiring two weeks of hemodialysis. Scanning with technetium-99m pyrophosphate revealed extensive muscle injury in the regions of cardioversion and a large anterolateral MI. Prolonged resuscitative efforts involving repeated cardioversion may predispose to myoglobinuric renal failure.