Brewer, Young, and Barnett reported a comprehensive psychometric evaluation of a new adult theory of mind measure (A-ToM) with a sample of high-functioning autism spectrum disorder (ASD) adults. Although correlations with existing theory of mind (ToM) instruments (i.e., the Strange Stories; the Frith- Happé animations) were reported, relationships with independent putative indicators of ToM development such as social-behavioral and interpersonal proficiencies were not examined. Here, we provide convergent validity data by examining the relations between A-ToM performance, and the social-behavioral skills and interpersonal relationships of ASD adults with IQs exceeding 85. ToM predicted interpersonal relationship quality via the mediating variable, social-behavioral skills, providing evidence of convergent validity for the A-ToM. Alternative models of the relationship between the three variables are described, as are the challenges associated with the interpretation of self-report social and interpersonal functioning measures.