Guatemala suffers the double burden of malnutrition with high rates of stunting alongside increasing childhood overweight/obesity. This study examines the school food environment (SFE) at low-income Guatemalan elementary schools and discusses its potential impact on undernutrition and overweight/obesity. From July through October 2013, direct observations, in-depth interviews with school principals (n = 4) and food kiosk vendors (n = 4, 2 interviews each) and also focus groups (FGs) with children (n = 48, 8 FGs) were conducted. The SFE comprises food from school food kiosks (casetas); food from home or purchased in the street; and food provided by the school (refacción). School casetas, street vendors and children’s parents largely provide sandwiches, calorie-rich snacks and sugar-sweetened beverages. Refacción typically serves energy dense atol, a traditional beverage. The current school food program (refacción), the overall SFE and the roles/opinions of vendors and principals reveal persistent anxiety concerning undernutrition and insufficient concern for overweight/obesity. Predominant concern for elementary schoolchildren remains focused on undernutrition. However, by the time children reach elementary school (ages 6–12+), food environments should encourage dietary behaviors to prevent childhood overweight/obesity.