Priapism and increased intracranial pressure are both rare, but recognized, manifestations of leukemia. However, they have never been reported in the same patient. We report a 15-year-old male with acute lymphoblastic leukemia who presented with hyperleukocytosis, priapism, and increased intracranial pressure. Central nervous system leukostasis and cerebral edema may have been detected earlier, had his history of priapism been known. Management of hyperleukocytosis complicated by priapism and increased intracranial pressure is discussed.