The aims of this study were to determine the sociodemographic and dietary correlates of household and child food insecurity in Bogotá, Colombia and to examine whether food insecurity is a risk factor for underweight or overweight in this population. We analyzed data from 2359 families with 2526 children 5-12 y of age who completed a cross-sectional survey conducted in 2006. The survey was representative of low- and middle-income families who had children enrolled in the public primary school system of Bogotá. We used a 16-item food insecurity scale, modified from the United States Household Food Security Survey Module, assessed children's dietary intake with a FFQ, and measured their height and weight. Mothers' anthropometry was obtained through self-report. We estimated adjusted prevalence ratios and 95% CI from binomial regression models. Household food insecurity with hunger and child food insecurity were each positively associated with maternal age, parity, and single parent status and inversely related to mean household income and number of home assets. Animal protein and snack food intake were inversely related to child food insecurity. In multivariate analyses, food-insecure children were 3 times more likely to be underweight than food-secure children (95% CI = 1.6, 5.4; P = 0.0007). Hunger in the household was significantly associated with maternal underweight. Food insecurity was not related to child stunting, child overweight, or maternal overweight. The prevalence of food insecurity in Bogotá is high and related to poverty. Food insecurity does not necessarily predict overweight in countries undergoing the nutrition transition.