Acute renal failure (ARF) is an important complication of rhabdomyolysis. However, the contributing factors to the development of ARF in children with rhabdomyolysis remain obscure. The aim of this study was to clarify the factors contributing to the development of ARF in children with rhabdomyolysis. This is a retrospective review of the clinical characteristics, laboratory data, pediatric risk of mortality (PRISM) scores, the occurrence of systemic inflammatory response syndrome (SIRS) criteria, and the number of dysfunctional organs in 18 children with rhabdomyolysis seen in our hospital between 1991 and 2000. The patients were divided into an ARF group (n=9) and a non-ARF group (n=9). All patients with ARF had more than two dysfunctional organs. The incidence of dehydration, serum concentrations of myoglobin, creatinine kinase, aspartate aminotransferase, and lactate dehydrogenase, PRISM scores, and the numbers of SIRS criteria and dysfunctional organs were higher in the ARF group than the non-ARF group. The blood pH and base excess, and urinary pH were lower in the ARF group than in the non-ARF group. These results suggest that ARF is more likely to develop in the presence of dehydration, metabolic acidosis, or severe muscle damage, or with multiple organ failure in children with acute rhabdomyolysis.