Objective. To examine the association between sweet drink consumption and overweight among preschool children. Methods. A retrospective cohort design was used to examine the association between sweet drink consumption and overweight at follow-up among 10 904 children who were aged 2 and 3 years and had height, weight, and Harvard Service Food Frequency Questionnaire data collected between January 1999 and December 2001 and height and weight data collected 1 year later. Sweet drinks included vitamin C-containing juices, other juices, fruit drinks, and sodas as listed on the Harvard Service Food Frequency Questionnaire. Logistic regression was used to adjust for age; gender; raceethnicity; birth weight; and intake of high-fat foods, sweet foods, and total calories. Results were stratified by baseline BMI. Results. Among children who were normal or underweight at baseline (BMI < 85th percentile), the association between sweet drink consumption and development of overweight was positive but not statistically significant. Children who were at risk for overweight at baseline (BMI 85th-< 95th percentile) and consumed 1 to < 2 drinksday, 2 to < 3 drinksday, and ≥3 drinksday were, respectively, 2.0 (95%confidence interval CI : 1.3-3.2), 2.0 (95%CI: 1.2-3.2), and 1.8 (95%CI: 1.1-2.8) times as likely to become overweight as the referent ( < 1 drink day). Children who were overweight at baseline (BMI ≥95th percentile) and consumed 1 to < 2 drinksday, 2 to < 3 drinksday, and ≥3 drinksday were, respectively, 2.1, 2.2, and 1.8 times as likely to remain overweight as the referent. Conclusions. Reducing sweet drink consumption might be 1 strategy to manage the weight of preschool children. Additional studies are needed to understand the mechanism by which such consumption contributes to overweight. To examine the association between sweet drink consumption and overweight among preschool children. Methods. A retrospective cohort design was used to examine the association between sweet drink consumption and overweight at follow-up among 10 904 children who were aged 2 and 3 years and had height, weight, and Harvard Service Food Frequency Questionnaire data collected between January 1999 and December 2001 and height and weight data collected 1 year later. Harvard Service Food Frequency Questionnaire. Logistic regression was used to adjust for age; gender; raceethnicity; birth weight; and intake of high-fat foods, sweet foods, and total calories. Results were stratified by baseline BMI. Results. normal or underweight at baseline (BMI <85th percentile), the association between sweet drink consumption and development of overweight was positive bu Children who were at risk for overweight at baseline (BMI 85th- <95th percentile) and consumed 1 to <2 drinksday, 2 to <3 drinksday, and ≥3 drinksday were, respectively, 2.0 (95% confidence interval CI: 1.3-3.2), 2.0 (95% CI: 1.2-3.2), and 1.8 (95% CI: 1.1-2.8) times as likely to become overweight as the referent (<1 drink day). Children who were overweight at Reduced sweet drink (2) <2 drinksday, 2 to <3 drinksday, and> 3 drinksday were, respectively, 2.1, 2.2, and 1.8 times as likely to remain overweight as the referent. consumption might be 1 strategy to manage the weight of preschool children. Additional studies are needed to understand the mechanism by which such consumption contributes to overweight.