Progress in the study of infantile autism over the past 10 years was reviewed in terms of classification and diagnosis, relation to other disorders, demographics, parental characteristics, genetics, intelligence, language, perceptual processes, behavioral characteristics, neurobiological, biochemical and pharmacological aspects, behavioral/educational treatment methodologies, prognosis, and theoretical considerations. This decade's research led to the now generally accepted position that infantile autism is a type of developmental disorder accompanied by severe and, to a large extent, permanent intellectual/behavioral deficits. However, its relationship to other forms of developmental disorders and to mental retardation remains to be delineated. Perceptual/cognitive/language defects appear central to the autistic syndrome, but the specific underlying mechanisms are unknown. Most studies indicate that autistic children have more signs of brain dysfunction than do normal children and about the same number as mentally retarded children. The overwhelming evidence suggests that te treatment of choice for maximal benefit to autistic children is a systematic, intrusive behavioral/educational approach. Yet, in spite of significant gains in almost all children treated, the typical prognostic picture is poor in terms of achieving self-supportive adulthood. The parents of autistic children have been found to be essentially similar to parents of children with organic brain disorders, and manifest no psychopathology which conceivably could induce the disorder. The vast majority of theoretical articles appearing in the 1970s proposed some from of neurobiological defect as the causative factor in autism. One of the major goals for future research is to undertake more extensive comparative studies on nonautistic brain dysfunctional children and autistic children that could yield cleared differential behavioral profiles and testable neurobiological hypotheses.