This study investigated longitudinal relationships between fathers' involvement, as measured by reading, and child socioemotional behavior between infancy and age 7 in 9,238 intact two-parent families from the U.K. Millennium Cohort Study, a national cohort of British children born between 2000 and 2002. Once a variety of covariates and the potential bidirectional nature of relationships were taken into account, a path model showed that fathers' involvement with their children in infancy significantly predicted better socioemotional behavior at age 3, although the relationship was not strong. Fathers' reading with their children between ages 3 and 7 was not significantly associated with child socioemotional behavior, but mothers' reading with their children at age 3 was significantly associated with improved child socioemotional behavior at ages 3 and 5. Results also suggested that parenting in the 21st-century British context remains fairly gendered. Both mothers and fathers were more likely to engage in physical activities with their sons and artistic activities with their daughters. Fathers' reading was socially patterned in predicted directions.