The triple association of leukemia, xanthomatous skin lesions, and neurofibromatosis 1 (NF) was first described by Royer et al. in 1958. Most of the leukemias were of the juvenile chronic myelogenous type (JCML). We describe a 7-year-old male child with xanthoma, neurofibromatosis 1, and juvenile chronic myelogenous leukemia. His mother also had NF1. We suggest that the presence of xanthomas and NF1 in a young child should raise awareness of the possible development of JCML, especially in patients with a family history of NF1.