Introduction: In the United States, child obesity has increased dramatically in the past 30 years. Among 2 to 5 year olds, the prevalence of overweight has increased two-fold, with the highest prevalence reported among Mexican Americans. In parallel with the increase in child obesity, soft drink consumption has also increased. The purpose of this study was to determine the association between current soda consumption and overweight in 2-year-old Mexican-American children. Methods: The CHAMACOS study is a longitudinal study of the health of low-income Latino pregnant women and their children living in an agricultural region of California. Six hundred pregnant women were enrolled between October 1999 and October 2000, and their children were followed until 2 years of age. This cross-sectional analysis includes the 354 children who completed the 2-year follow-up interview. Standing height (cm) and weight (g) were measured at 2 years. Overweight was defined as = 95th percentile of the sex-specific body mass index for each child's age. Results: At 2 years of age, fifty-five (15.5%) children were overweight. Over half (56%) reported consuming any soda in the last seven days, with an average consumption of 0.51 (S.D.= +/-0.53) sodas per day. After adjusting for covariates, < 1 soda per day, compared to no soda consumption, was not related to overweight status (adj-OR = 0.97, 95% CI 0.47, 1.99), but =1 soda per day was significantly associated with overweight (adj-OR = 3.39, 95% CI 1.43, 8.07) and the test for trend was significant (p = 0.02). Discussion and Conclusions: At 2 years of age, the prevalence of overweight among the CHAMACOS cohort is higher than the national prevalence estimate for Mexican-American, 2-5 year olds, and is significantly associated with current soda consumption. These findings highlight the need for interventions to reduce consumption of soda in preschool-age Mexican-American children.