A newborn presented on the 12th day of life with clinical and laboratory manifestations of leukemia. Autopsy the following day revealed hematopoietic activity in the liver, spleen, lymph nodes, kidney, pancreas, and heart, compatible with myeloid metaplasia. The marrow was not leukemic. Fibrosis was absent. Causes of myeloid metaplasia were excluded as far as possible. The similarity of this case to recently reported patients with Down's syndrome and leukemic-like myeloproliferative disorders is discussed.