This study explores the relationship between preschool children's math interest and their current and future mathematical ability. The project takes place in the context of a larger math skills intervention study that was designed in collaboration with Holyoke-Chicopee-Springfield Head Start. Participants include approximately 120 3-5-year-old children from eight Head Start classrooms. The study uses a cross sectional and a longitudinal correlational design. Child assessments include a quasi-naturalistic observation of math play, math interest self-reports, the Test of Early Math Abilities (TEMA-2) and a portion of the Kaufman Survey of Early Academics and Learning (KSEALS). The children were assessed in early winter and again in the late spring. Teachers were asked to complete two different math interest scales for each child in early winter and late spring. Relationships between the following variables are examined: (1) early math interest and concurrent math skills, (2) early math interest and later math skills, (3) early math ability and later math interest, and (4) gender and math interest. In addition, the study investigates gender differences as a possible moderating variable in the relationship between interest and math ability.