The authors report two cases of Erdheim-Chester disease (ECD), an illness of unknown pathogenesis. Generally, this disease process involves the metaphyseal and diaphyseal portions of the long bones, the lungs, and the retroperitoneum; however, other tissues may be involved including the central nervous system (CNS). To date only two cases of CNS-related ECD have been reported. The present report adds to the literature by documenting two more recent cases of ECD involving the CNS. The clinical presentations of these cases, their radiological findings with special reference to magnetic resonance imaging, pathological determination, and clinical management are briefly reviewed.