Father involvement is a salient predictor of children’s cognitive development and recent studies suggest that African American and Hispanic fathers, who are highly involved, have children who enter school more poised to succeed. Little is known, however, about contextual barriers to positive father involvement in ethnic minority families. This study examined prospective relations between fathers’ work characteristics (i.e., total work hours per week, job satisfaction, and work shift) and children’s cognitive development in preschool (i.e., reading and math scores). A total of 2,340 children were included in the study (35% African American, 65% Hispanic). Fathers’ total work hours per week positively predicted children’s reading and math scores. Fathers’ work shift (i.e., nonstandard) positively predicted reading, but not math. In contrast, fathers’ job satisfaction negatively predicted children’s math achievement. Findings were evident even after controlling for a host of demographic factors (e.g., father education, mother education, home-learning environment, and family income).