The social self-preservation theory states that humans have a fundamental motivation to preserve the social self and that threats to the social self perturb biological markers such as cortisol. Five studies were designed to examine the cortisol response to competitive ballroom dancing as a paradigm for real-life social-evaluative threat. Competitive dancing produced substantial increases in cortisol compared to a control day. These increases were not due to the physical strain of dancing and were greater than those found during social-evaluative laboratory stressors. Responses did not habituate across competitions and were mostly elevated under highly focused conditions of threat (couple vs. group competition). These findings support the notion of a social self-preservation system that is physiologically responsive to threats to the social self.