Hemolymphoproliferative diseases (HLD) are among the most common causes of morbidity and mortality in children. In the past few years, the increased effectiveness of treatment modalities has significantly increased overall survival, but has also disclosed new aspects of the natural history of these disorders, among which central nervous system (CNS) involvement. CNS complications of HLD can basically be categorized into direct localization of primary disease, indirect effects of malignancy such as cerebrovascular or infectious complications, and iatrogenic side effects. Magnetic resonance imaging plays an important, often crucial role in the diagnosis of several of these disorders. Close interdisciplinary collaboration between hemato-oncologists and neuroradiologists is of paramount importance to provide affected children with an early diagnosis and proper treatment.