Central diabetes insipidus (DI) is well-documented as a presenting feature of myelodysplastic syndrome and acute myeloid leukemia in adults. However, DI is unusual in pediatric patients with myeloid malignancies. We report here this rare complication in a child with neurofibromatosis type 1 who developed juvenile myelomonocytic leukemia and monosomy 7. Our case and previously reported cases of DI arising as a complication in myeloid malignancies demonstrate a close association with deletion of chromosome 7. The clinical characteristics and outcomes of these uncommon cases in children are reviewed and discussed.