Rhabdomyolysis, both traumatic and nontraumatic, may be defined as a triad of skeletal muscle injury, pigmented urine, and acute renal failure. Nontraumatic rhabdomyolysis may be more of a subtle diagnosis and requires a high index of suspicion. Pertinent findings in the history as well as clinical evidence of muscle injury with a marked elevation of creatinine kinase will suggest the diagnosis. A disproportionate elevation of serum creatinine to blood urea nitrogen may also occur. Treatment consists of adequate hydration to help prevent oliguric or anuric renal failure without additional calcium or bicarbonate supplementation in most cases. Radiologic studies involving intravenous contrast media as well as urologic instrumentation should be avoided in the acute setting. With early diagnosis and prompt treatment the prognosis for recovery is excellent.