The spectrum of the possible manifestations of Langerhans' cell histiocytosis in children is very wide, ranging from a simple rash to major multiorgan disease. There may be hypothalamic and pituitary dysfunction or more global neurological and neuropsychiatric manifestations when the central nervous system is affected. The cerebellum is preferentially affected for yet undetermined reasons. The clinical presentation includes motor dysfunction as well as cognitive, behavioral, and psychiatric expression of the ongoing neurodegeneration. We report a young patient with Langerhans' cell histiocytosis who underwent an unusual course of psychiatric deterioration.