A longitudinal study was conducted of 243 children with congenital rubella. In this sample a high rate of autism and a high rate of recovery were observed. Examination of the data suggested that the rubella virus was the primary etiologic agent. It is hypothesized that the course of autism was that of a chronic infection in which recovery, chronicity, improvement, worsening, and delayed appearance of the autistic syndrome all were found. Other rubella consequences such as blindness, deafness, and cardiac and neuromuscular defects remained present except as modified by operations and prostheses. Degree of mental retardation initially was related to the outcome of autism but shifts in mental retardation over time did not correlate significantly for the group with shift in the autistic symptoms.