Both high-functioning autism (HFA) and social phobia (SP) involve profound social interaction deficits. Although these disorders share some similar symptoms, they are conceptualized as distinct. Because both HFA and SP are defined behaviorally, the degree of overlap between the two disorders may result in misinterpretation of symptoms. However, the deficits in each disorder differ, particularly in areas of social interaction, emotion recognition and expression, and communication. This paper reviews the literature that informs our current understanding of the behavioral overlaps and differences in HFA and SP. The review also addresses the implications of our current knowledge of these two disorders for differential diagnosis, treatment, and future research. Interdisciplinary, developmentally-oriented research may help extend current approaches to HFA and SP.