Maternal depression negatively impacts children's development, yet few studies have focused on fathering and the family process in cases of maternal depression. A community cohort of married/cohabitating women was recruited on the second postbirth day (N = 1,983) and maternal depression repeatedly assessed across the first year and again at 6 years to form two cohorts: mothers chronically depressed from birth to 6 (N = 46) and nondepressed controls (N = 103). At 6 years, mother-child, father-child, and family interactions were observed. In families of depressed mothers, both mother and father exhibited lower sensitivity and higher intrusiveness, and children displayed lower social engagement during interactions with mother and father. Fathering moderated the effects of maternal depression on the family process. When fathers showed low sensitivity, high intrusiveness, and provided little opportunities for child social engagement, the family process was less cohesive, implying a decrease in the family's harmonious, warm, and collaborative style. However, in cases of high father sensitivity, low intrusiveness, and increased child engagement, the family process was unaffected by maternal depression. Findings describe both comparability and compensatory mechanisms in the effects of fathering on family life when maternal care is deficient, highlight the buffering role of fathers, and underscore the importance of father-focused interventions when mothers are depressed.