In the present study, we examine the associations between the amount of time that U.S. employed fathers took off from work after the birth of a child (i.e., paternity leave-taking) and trajectories of how frequently fathers engage with their children and take responsibility for them. To do so, we analyze longitudinal data on 2109 fathers from the Fragile Families and Child Wellbeing Study, a data set that contains information from disproportionately socioeconomically disadvantaged families from large urban areas. The results indicate that, 1 year after birth, paternity leave-taking and lengths of leave are positively associated with fathers’ engagement and responsibility. In addition, paternity leave-taking is positively associated with trajectories of fathers’ responsibility over the first 5 years after birth. Lengths of paternity leave are positively associated with trajectories of fathers’ engagement. Finally, there is evidence that paternity leave-taking and lengths of leave-taking are especially likely to boost fathers’ engagement and responsibility among nonresident fathers. Overall, the findings from the present study suggest that an expansion of paternity leave-taking may encourage higher subsequent levels of father involvement—especially among nonresident fathers.