In preschool, learning often occurs within the context of children’s play activities with various toys and materials. Although much theoretical speculation has occurred, relatively little empirical research has examined how preschoolers’ play activities foster children’s learning and academic skill development. The current study extended previous research on dimensions of adolescent activity involvement to young children in preschool by assessing dimensions of activity involvement across and within curriculum-based and gender-based activity domains. In a longitudinal design, I explored the relation between these dimensions of activity involvement in the fall semester of children’s preschool year and children’s academic outcomes at the end of their preschool year. Participants included preschool children (n = 279; M age = 52 months, 47% girls, 70% Mexican or Mexican-American) from lower socioeconomic status families. Children’s activity involvement was observed, and academic abilities were assessed through child interviews and teacher reports. The results provided little evidence to support the hypotheses that children’s dimensions of activity involvement in the fall semester of their preschool year contributed to their academic abilities in literacy and mathematics at the end of their preschool year. Findings were discussed in terms of the strengths and limitations of the present study. Potentially important steps remain for research on the relation between preschool activity involvement and academic abilities.