Objective: Determine child/maternal factors associated with overweight among 2- to 4-year-olds enrolled in the Texas Special Supplemental Nutrition Program for Women, Infants, and Children (WIC). Design: Matched child and maternal data collected by self-report of the mother during WIC certification. These data were extracted from existing statewide WIC databases and merged. Setting: Texas WIC children aged 2 to 4 years in April 2006. Participants: Final sample was 22,837 mother-child dyads. Main Outcome Measure: Dependent variable--child overweight; independent variables: Child-related--gender, age, race/ethnicity, Medicaid status, living area, and dental problems; Maternal-related--certification status, age, times certified, overweight, high maternal weight gain, and gestational diabetes. Analysis: Bivariate relationships at P less than 0.05 were included in the logistic regression. Results: Living in a nonborder urban area associated with greater odds of overweight compared to living in a border area. Mother's overweight, high gestational weight gain, and gestational diabetes associated with greater odds of child overweight. Conclusions and Implications: Several child- and maternal-related factors were found to be associated with overweight in Texas WIC preschoolers. Health interventions should target 4-year-old Hispanic children living in nonborder urban areas and mothers who are overweight, have high gestational weight gain, or have gestational diabetes. (Contains 3 tables.)