<p>New mothers navigating the demands of infant care often experience heightened responsibility and adjustment-related burden, which may be associated with maternal depressive symptoms. These symptoms may extend beyond the immediate postpartum period and have important implications for parenting practices, the mother–child relationship, and child development. This study examined whether marital satisfaction, parenting stress, and parenting attitudes were associated with maternal depressive symptoms among 1,628 South Korean mothers of children aged 1–36 months. Participants completed the Marital Satisfaction Scale, selected subscales from the Maternal Behavior Research Instrument, the Parenting Stress Index, and the Beck Depression Inventory. Results indicated that lower marital satisfaction and higher parenting stress were significantly associated with higher levels of maternal depressive symptoms across all age groups. Age-differentiated patterns also emerged for parenting attitudes. Mothers’ emphasis on the child’s intellectual achievement was more strongly associated with depressive symptoms among mothers of children aged 13–24 and 25–36 months than among mothers of children aged 1–12 months. In addition, less positive perceptions of mothers’ own intellectual ability were significantly associated with higher depressive symptom levels among mothers of children aged 25–36 months. Together, these findings suggest that maternal depressive symptoms during early child-rearing are related not only to general relational and parenting stressors but also to age-specific parenting concerns. The findings highlight the importance of considering the child’s developmental stage when assessing maternal depressive symptoms and designing age-sensitive supports for mothers during the first three years of life.</p>