This study examined the relationship between social fears and the three subscales of the Anxiety Sensitivity Index (ASI) in a non-clinical, student sample. In particular, the unique variance that the three ASI factors accounted for in social scrutiny fears, social interaction fears, and fear during a social challenge was investigated. Anxiety Sensitivity-Social Concern (AS-Social Concern) was hypothesised to account for a significant proportion of the variance in social fears compared to the other two subscales. Seventy one university students completed a series of psychological-based questionnaires and participated in a social challenge (videotaped speech task). Contrary to prediction, AS-Social Concern did not account for a unique proportion of the variance in social fears, but AS-Physical Concern and AS-Mental Concern did account for unique variance in social fears. Results are interpreted in light of recent findings on the structure of ASI.