The article presents information from two studies of a research program investigating psychosocial antecedents of athletic injury. Study 1 describes the development of the Life Events Survey for Collegiate Athletes (LESCA). The LESCA demonstrated good content validity and provided a stable measure of life stress. The LESCA's validity and the moderating effects of social support were explored in the second study. The LESCA provided a construct-valid measure of life stress and was a better predictor of athletic injury than the Social and Athletic Readjustment Rating Scale. Social support moderated the stress-injury relationship in such a way that LESCA negative life stress accounted for 11% to 22% of injury variances in low-support conditions; LESCA positive life stress accounted for 14% to 20% of injury variances in high-support conditions. Mechanisms underlying the stress-injury relationship and directions for future research are discussed with respect to the model outlined by M. B. Andersen and J. M. Williams in 1988.