A 16-year-old girl with anorexia nervosa first presented with malnutrition, liver dysfunction, and rhabdomyolysis. Administration of fluid and nutrition saved her from the initial critical state, but acute renal failure followed. Laboratory examination revealed intrinsic renal failure induced by rhabdomyolysis. Latent phosphate depletion and refeeding-induced hypophosphatemia was implicated as the cause of rhabdomyolysis; however coexisting hypotension, dehydration, and liver dysfunction may have contributed to the renal failure. The patient recovered from azotemia by hemodialysis. This is the first reported case of anorexia nervosa with acute renal failure resulting from rhabdomyolysis induced by hypophosphatemia or phosphate depletion.