This study explored the involvement of grandparents in the care for young children and its effect on subsequent child births in dual-earner families, using data on 898 Dutch men and women aged 18–49 from the Netherlands' Kinship Panel Study. Three theoretical perspectives were used to develop hypotheses: (a) needs and opportunities, (b) normative preferences, and (c) gendered involvement of grandparents. The findings showed that needs and opportunities informed involvement of grandparents but that the availability of formal child care did not predict grandparents' involvement. Maternal grandparents were more likely to provide child care than paternal grandparents, and grandmothers were more likely to do so than grandfathers. Involvement of both maternal and paternal grandparents in turn increased the likelihood of additional child births. The authors conclude that grandparental child care may be part of an emerging reproductive strategy. Implications of these findings for the theoretical approaches used are discussed.