Familial erythrophagocytic lymphohistiocytosis is a fatal early childhood disorder characterized by multiorgan lymphohistiocytic infiltration and active hemophagocytosis. Involvement of the central nervous system (CNS) is not uncommon and is characterized by rapidly progressive tissue damage affecting both the gray and white matter. We encountered a case of familial erythrophagocytic lymphohistiocytosis with CNS involvement. Initial T2-weighted MRI of the brain demonstrated high signal intensity in the right thalamus, though after chemotherapy, which led to the relief of neurologic symptoms, this disappeared. After four months, however, the patient's neurologic symptoms recurred, and follow-up T2-weighted MR images showed high signal intensity in the thalami, basal ganglia, and cerebral and cerebellar white matter. Brain MRI is a useful imaging modality for the evaluation of CNS involvement and monitoring the response to treatment.