A case of disseminated Langerhans cell histiocytosis with resistant central nervous system (CNS) disease in an adolescent is described. The child presented with visible cranial lesions, emesis, headaches, and short-term memory loss. Diagnostic evaluation revealed multiple osseous lesions in the cranium, ribs, vertebral bodies, and pelvis. The clinical course with complications and response to each therapy are sequentially reviewed. Remission, as evidenced clinically and by magnetic resonance imaging, was ultimately accomplished with 2-chlorodeoxyadenosine (2-CDA). The full course of 2-CDA was not tolerated due to bone marrow suppression. CNS histiocytosis is known to be resistant to therapy. Earlier introduction of 2-CDA for CNS disease might offer more successful treatment with less toxicity than seen in patient.