Literature suggests that young children have a significant influence on activity patterns and time-use of adult men and women in dual-earner households. The resultant impact on travel behavior, however, remains largely unexplored. In this study, we use the 2012–13 California Household Travel Survey to compare daily (weekday) travel behavior of adult men and women belonging to dual-earner heterosexual couple households without children, with their adult counterparts in dual-earner heterosexual nuclear households with one or more young (aged 15 years or less) children living in urban California. We find that the presence of young children is, on average, associated with relatively higher auto use, and lower levels of physically active travel (i.e., walking and bicycling) and public transit use. Specifically, parents of school-age (6–15 years) children, without other small (5 years or less) children, are found to engage in significantly more auto use than childless couples. The likelihood of engaging in 20 min or more of active travel per day falls as couples transition to parenthood, and drops further as small children turn school-age. The likelihood of making at least one transit trip per day follows a similar pattern. We also find that the negative impact of young children on average, and school-age children in particular, on adults’ active travel is significantly greater for men than women. Additionally, we identify factors that can help reduce gender inequality in auto use and active travel within households with one or more young children. This study enhances our understanding of travel behavior variations across household types in cities, and over the life courses of individuals. Planning and policy implications are discussed.