OBJECTIVE: To determine if breastfeeding for at least the first six months of life is associated with overweight and obesity in children 2 to 5 years old. METHOD: Cross sectional analysis of data from national demographic and health surveys conducted in Bolivia, Colombia and Peru. Overweight and obesity were defined using World Health Organization standard definitions. Odds ratios (OR) were calculated using multinomial logistic regression. RESULTS: The prevalence of obesity in children 2 to 5 years old was 10.4% (95% confidence interval [95%CI]: 8.2-12.6) in Bolivia, 4.9% in Colombia (95%CI: 4.0-5.8), and 6.4% (95%CI: 5.2-8.0) in Peru. Prevalence of exclusive breastfeeding for at least the first 6 months in the study population was 89.9% (95%CI: 87.8-91.9) in Bolivia, 73.9% (95%CI: 72.2-75.6) in Colombia, and 92.8% (95%CI: 91.2-92.4) in Peru. Exclusive breastfeeding was associated with a decreased risk of obesity in children as compared to no breastfeeding or breastfeeding for less than 6 months in Bolivia (OR = .30; 95%CI: .16-.57) and a marginal association in Colombia (OR = .71; 95%CI: .47-1.06) and Peru (OR = .49; 95%CI: 0.23-1.04). No association between breastfeeding and overweight was found. CONCLUSION: Exclusive breastfeeding for at least the first six months of life decreases the risk of obesity in children 2 to 5 years old in Bolivia. A similar but weaker pattern was observed for children in Colombia and Peru.