Despite perceptions that infidelity is common among military and veteran populations, there is relatively little evidence documenting the prevalence of extramarital sex among persons with a history of military service or its consequences for marital stability. Using data from the 1992 National Health and Social Life Survey, we estimate multivariate logistic regression models to examine the associations between veteran status, extramarital sex, and divorce among ever-married persons aged 18 to 60 years. We also conduct supplemental analyses of gender differences. We find that 32.17% of veterans report extramarital sexual relationships, which is twice the rate among nonveterans in this sample. Controlling for sociodemographic and early-life factors, veterans are significantly more likely than nonveterans to report extramarital sex and to have ever divorced, whereas extramarital sex has a strong, independent association with divorce. We conclude that veteran status is strongly associated with extramarital sex and divorce, at least among men; extramarital sex and divorce might also be elevated among female veterans, but research that uses larger, representative samples of female veterans is needed to confirm those associations. The higher rates of infidelity among veterans may be related to selection factors; military experiences, such as deployment; or postmilitary factors. The current research provides a foundation for further research that aims to explicate the mechanisms underlying this association.