The first year of parenthood can be a stressful time, especially for high-risk couples. Symptoms of posttraumatic stress (PTS) have been associated with decreased intimacy, communication, and relationship adjustment, yet there is a lack of research on how PTS symptoms might affect couples in early parenthood. Furthermore, there is little evidence regarding the way in which PTS symptoms may affect couples above and beyond known risk factors such as intimate partner violence (IPV) and harmful alcohol use. The current study investigated how PTS symptoms were related to new parents’ relationship satisfaction in the context of IPV and harmful drinking. Ninety-eight heterosexual couples filled out questionnaires 1 year after the birth of their first child. Hierarchical multiple regression analyses indicated that, for men, PTS symptoms predicted lower relationship satisfaction over and above IPV victimization and harmful drinking. However, for women, psychological IPV victimization was the only significant multivariate predictor. In addition, for men, PTS symptoms interacted with harmful drinking to predict poorer relationship satisfaction. The results suggest that women’s relationship satisfaction is particularly linked to psychological IPV victimization during early parenthood, whereas men’s relationship satisfaction is particularly associated with their own harmful drinking and PTS symptoms. Implications are discussed.