Two patients who presented with acute leukemia of Burkitt's cell type are discussed. Although one patient died within four months of diagnosis, the other has maintained a one year clinical complete remission. The clinical and morphologic picture of Burkitt's leukemia is nonspecific and therefore requires complementary studies including cytochemistry, transmission electron microscopy, cell surface markers and cytogenetics studies to establish diagnosis. Serial bone marrow aspirations with marker analyses may detect relapse at an earlier stage than conventional cytology, allowing therapy to be modified prior to overt clinical relapse.