We report two cases of Langerhans' cell histiocytosis with unusual central nervous system (CNS) involvement. The first patient had behavioural disturbances, memory loss and diabetes insipidus. His response to a range of treatments was poor. The second patient presented with seizures and headaches suggestive of raised intracranial pressure. Etoposide (VP16) chemotherapy led to a dramatic clinical and radiological improvement. The various CNS manifestations of Langerhans' cell histiocytosis and their management are discussed.