Having a poor relationship with one’s romantic partner has been shown to have several deleterious effects on psychological and behavioral health outcomes during pregnancy (e.g., depression, stress, and drug use). Despite these effects, there are few studies to date that have examined the impact of prenatal stress management programs on poor relationship quality during pregnancy. The current study investigated whether changes in the quality of the relationship with one’s partner, as a result of participation in a prenatal cognitive behavioral stress management (CBSM) program, was associated with reductions in perceived and physiological (salivary cortisol) stress levels among a sample of low-income pregnant women (N = 97). Results provide support for implementing prenatal programs focused on improving relationship satisfaction and health outcomes for women and their families.