The purpose of the present study was to develop and evaluate a measure of defense mechanisms that is useable in sports research: the short Defense Style Questionnaire (DSQ-26). A total of 296 competitive athletes completed the DSQ-26 and other self-report questionnaires both before and after a sport competition. Results of Principal Component Analyses (PCA) on the pre-competitive data showed evidence for a 2-factor model that included adaptive (e.g., humor, anticipation, self-assertion, altruism, self-observation) and maladaptive defenses (e.g., help rejecting complaining, splitting other, projection, dissociation, intellectualization, devaluation/self, fantasy, devaluation of other). Confirmatory factor analyses conducted on both the pre- and intra-competitive data showed an acceptable fit of the data for the 2-factor, 13-defense model of DSQ-26, supporting the factorial structure identified within the PCAs. Correlations between DSQ-26 subscales, coping, affective states, perceived stress and control scores provided evidence for criterion-related validity of the DSQ-26 scores. Overall, this study provides support for the reliability and validity of the short DSQ-26 scores with recommendations for the use and development of this measure of defense mechanisms in stressful situations.