Social anxiety disorder (SAD) is a common comorbidity for individuals with autism spectrum disorder (ASD). The present study examined the cardinal cognitive component of SAD, fear of negative evaluation (FNE), in adolescents and adults with ASD (n = 44; 59 % with social anxiety) and those without ASD (n = 69; 49 % with social anxiety). Group (ASD or non-ASD) significantly moderated the relationship between social disability, as well as social motivation impairment, and FNE, such that there was a stronger positive relationship for the adolescents and adults without ASD. Few differences emerged between those with and without ASD, with respect to specific indicators of FNE. Clinical implications are discussed, including the importance of assessing FNE among individuals with ASD.