ObjectivesThe demand on Japanese women to fulfill their dual roles as mothers and labor force participants leads to a subsequent reduction of their employment hours, switching of occupations, or quitting the labor force. This study aims to examine paternal factors associated with mothers' employment status 18 months after childbirth.MethodsWe used data from the 2010 cohort of the Longitudinal Survey of Newborns conducted in Japan. We restricted our analysis to 10 712 mothers who had full‐time employment 1 year before childbirth. A logistic regression analysis was conducted to assess paternal factors associated with mothers' employment after childbirth.ResultsOne‐third of the mothers with full‐time employment before childbirth were not working full‐time 18 months after delivery. We found that high childcare involvement (score 13–18) of fathers (OR, 1.20; 95% CI, 1.01–1.43) and fathers with part‐time employment (OR, 1.59; 95% CI, 1.12–2.26) were associated with higher odds of mothers' full‐time employment. Fathers' weekly work of ≥60 h (OR, 0.79; 95% CI, 0.71–0.88) and higher annual income decreased the odds ratios by over 20%.ConclusionsFathers' work arrangements and involvement in childcare play a key role in helping mothers resume employment postchildbirth.