Forty cases of disease of the central nervous system, characterized by several episodes and disseminated lesions, with onset in childhood and clinically typical of multiple sclerosis, were studied. The disease as it occurs in children does not appear to differ clinically from the disease as observed in adults, in respect to mode of onset, symptoms, physical findings, and changes in the spinal fluid. In the Mayo Clinic series, however, almost twice as many girls as boys were affected. A pediatrician confronted with a child showing evidence of scattered neurologic deficits that remit, particularly a disturbance of vision and co-ordination, should consider the possibility of multiple sclerosis.