The increase in endogenous uric acid production in leukemic patients has long been a fact of considerable interest. The combination of even further production of endogenous uric acid induced by therapy and renal insufficiency is one which has been observed to lead to serious and, at times, fatal complications.1With newer chemotherapeutic agents in use for the treatment of the lymphomas and leukemias, drugs which are capable of depressing the white blood cell count more rapidly than x-rays, there is need for increased awareness of the possibility of uric acid obstruction of the urinary tract with subsequent uremia. We believe the following to be a case in point. REPORT OF A CASE C. M., a white woman aged 54, was first seen in the Diagnostic Clinic of Memorial Hospital on May 17, 1949. She gave a history of abdominal pain and progressive weight loss of one and one-half years'