An 11-year-old girl who presented with hyperleukocytosis accompanied by significant increases in serum uric acid and lactate dehydrogenase levels was discovered to be suffering from acute myeloid leukemia (AML). Subsequently a staghorn calculus was identified 22 months after the start of chemotherapy. The diagnosis of staghorn calculi was suggested by plain abdominal X-ray and ultrasonography. This paper describes the course of an adolescent patient with AML and focuses specifically upon her urological complications. To the best of our knowledge, this is the first reported pediatric case of AML complicated with staghorn calculi, which developed following repeated episodes of septicemia.