A four-month-old infant was hospitalized because of RSV bronchiolitis. Two days after presentation he developed rhabdomyolysis, most probably as a result of multiple factors (hyperthermia, hypovolemia/dehydration, hypernatremia, metabolic acidosis), followed by severe complications including acute renal failure, hepatic dysfunction and disseminated intravascular coagulation. Under sufficient fluid supply he recovered completely. In rhabdomyolysis clinical symptoms vary. Seldom, the classical trial of muscle pain, weakness, and dark urine is observed. Severe complications are hypovolemia, electrolyte disorders, a compartment syndrome, disseminated intravascular coagulation and acute renal failure, which causes death in 20% of the patients, although non-traumatic causes seem to have better outcome. The mainly therapeutic option is to correct the hypovolemia with sufficient fluid supply.