We present a first report of a CD7+ acute myelogenous leukemia patient who developed intracranial myeloblastomas. The patient was neurologically normal on physical examination at presentation. The peripheral leukocyte count was extremely high (203.6 x 10(9)/l). The blasts expressed CD7 and CD56 (neural cell adhesion molecule) in addition to CD13, CD33, CD34, and HLA-DR. The karyotype of bone marrow cells was normal. The patient was diagnosed as having acute myelogenous leukemia (AML, M1). Following a short period of complete remission, bone marrow relapse and meningeal leukemia occurred, and the patient died of respiratory failure. Autopsy revealed that blasts had invaded the subarachnoid space and cerebellum, and two myeloblastomas were found in the cerebellar hemisphere. Both CD7+ and CD56+ AML have been reported to have a high incidence of central nervous system involvement. CD7+ CD56+ AML calls for prophylaxis of central nervous system leukemia.