A 15-year old girl with slowly progressive gait and speech disorders, and with impairment of mental ability, is decsribed. The disease appeared 18 months before the first hospitalization at the Department of Neurology and Physchiatry for Children and Young People. Neurological and other examinations confirmed extrapyramidal and cerebellar signs, conspisuous knee and ankle reflexes, marked splenomegaly, slightly enlarged liver, sometimes emotional incontinence and global physic deterioration. The clinical picture was similar to Wilson's disease. However, in liver and bone marrow, as well as during sternal pincture macrophages (foam cells) were detected as characteristic elements of Niemann-Pick disease. The authors conclude that the patient belongs to type C of Niemann-Pick disease with a relatively benign course.