We assessed prevalence and correlates of differential maternal‐infant bonding (i.e., experiencing a stronger bond with one baby vs. the other) in mothers of twins, focusing on aspects of maternal mental health, well‐being, and pregnancy/birth that have been previously linked with maternal‐infant bonding. Participants (N = 108 American women, 88.89% White, 82.41% non‐Hispanic, aged 18–45, who gave birth to twins in the past 6–24 weeks) were recruited from postpartum support websites. Participants completed a Qualtrics survey assessing pregnancy/birth history, symptoms of depression and anxiety, sleep, stress, romantic relationship satisfaction, and postpartum bonding. Twenty‐six participants (24.07%) reported a bonding discrepancy. These participants endorsed higher symptoms of depression and anxiety, lower relationship satisfaction, lower average postpartum bonding, higher general and parenting stress, and longer pregnancy (all ps > .05). Greater degree of bonding discrepancy correlated with more depression, higher parenting stress, longer pregnancy, and lower relationship satisfaction (all ps > .05). Mothers of twins may benefit from postpartum mental health support, stress management strategies, and interventions to improve bonding. Future work should assess the role of breastfeeding difficulties, delivery method, birth‐related trauma, infant regulatory capacity, and temperament. Longitudinal studies will help test cause and effect and potential long‐term repercussions of maternal‐infant bonding discrepancies.