Background Social evaluative threat activates the HPA-axis system, namely cortisol and dehydroepiandrosterone (DHEA) responses. Additionally, cognitive and behavioral models in social anxiety, which is aroused anxiety symptoms in social situations, indicate that negative cognitions have a role in the maintenance of symptoms. Thus, the present study examined the relationship between HPA-axis activity and cognitive features in social situations. Method We conducted the Trier Social Stress Test (TSST) with 44 male participants and assessed HPA-axis responses, fear of negative evaluation, the estimated social cost, and self-perceptions of their speech performance, which are core negative cognitions in social situations. Results Results revealed that the cortisol-DHEA ratio significantly correlated with self-perceptions of participants’ speech performance ( r = .30, p = .044) and the discrepancy between self-ratings and others’ ratings of the speech ( r = .44, p = .003). After controlling for depressive symptoms, significant correlations remained ( r = .39, p = .01 and r = .50, p = .001, respectively). In addition, the estimated social cost, assessed before the speech task, significantly correlated with both the AUCg cortisol ( r = .38, p = .011) and cortisol-DHEA ratios ( r = .40, p = .007). Conclusion These results suggest that estimating social costs in social situations, as well as distorted self-perceptions of that stressor, is related to dysfunctional endocrine regulation.