Patients with anorexia nervosa exhibit acid-base and electrolyte disturbances. Hypophosphatemia is commonly found in these patients during nutritional recovery. However, marked, possibly, life-threatening hypophosphatemia associated with proximal tubular dysfunction has not been previously described. We report a case of anorexia nervosa complicated by a nonacidotic proximal tubulopathy, which was manifested by renal glycosuria, as well as inappropriate phosphaturia and uricosuria resulting in hypophosphatemia and hypouricemia. © 2001 by John Wiley & Sons, Inc. Int J Eat Disord 30: 227–230, 2001.