Objective To examine prospectively the association between beverage consumption (fruit juice, fruit drinks, milk, soda, and diet soda) and changes in weight and body mass index among preschool children. Design A prospective cohort study that collected dietary, anthropometric, and sociodemographic data. Subjects/Setting The study population included 1,345 children age 2 to 5 years participating in the North Dakota Special Supplemental Nutrition Program for Women, Infants, and Children (WIC) on two visits between 6 to 12 months apart. Statistical analyses We performed linear regression analyses to examine whether beverage consumption was associated with annual change in weight and body mass index. Intakes were measured as continuous (oz/day) and we also dichotomized fruit juice, fruit drinks, and milk at high intakes. Results In multivariate regression analyses adjusted for age, sex, energy intake, change in height, and additional sociodemographic variables, weight change was not significantly related to intakes (per ounce) of fruit juice (β=0.01 lb/year, 95% CI: -0.01 to 0.20, P=.28), fruit drinks (β=-0.03 lb/year, 95% CI: -0.07 to 0.01, P=.28), milk (β=0.00 lb/year, 95% CI: -0.02 to 0.02, P=.86), soda (β=-0.00 lb/year, 95% CI: -0.08 to 0.08, P=.95), or diet soda (β=0.01 lb/year, 95% CI: -0.11 to 0.13, P=.82). Findings remained null when we examined associations with body mass index and when fruit juice, fruit drinks, and milk were dichotomized at high intake levels in both analyses. Conclusions Our study does not show an association between beverage consumption and changes in weight or body mass index in this population of low-income preschool children in North Dakota.