This longitudinal study investigated marital satisfaction trajectories across the first 2 years of parenthood. Data were collected from new parents (couples) 6 weeks before the birth of their first child, and then at 6, 12, 18, and 24 months postpartum. Growth curve models revealed two key findings. First, for highly anxious individuals, satisfaction was lower or declined when they perceived their partners as less supportive and as behaving more negatively toward them. Second, for highly avoidant individuals, satisfaction was lower or declined when they perceived more work–family conflict and greater demands from their families. The findings suggest that attachment insecurities predict dissatisfaction in new parents primarily when stressors block the pursuit of important attachment goals.