Objective: To establish the relationship between sleep duration, nutritional status and caffeinated beverage consumption patterns in school-age Chilean children. Method: The study was conducted in 805 school-age children, between 6- and 10-years old from 6 neighbor-hoods in Santiago, Chile. Parents completed a questionnaire, which assessed sleep duration, physical activity and food intake. Anthropometric measurements were completed for children. Results: 52.6% of school-age children were obese and 46.4% slept the recommended amount (>= 10 hours). Normal weight subjects slept significantly more hours than obese participants, 9.8 +/- 0.9 vs. 9.6 +/- 0.9, respectively. Sleep duration during the week was inversely associated to obesity (OR: 3.5, 95% CI 1.3-9.2). Children drank the following beverages at night: caffeinated soft drinks (52.2 %), coffee and/or tea (32.6%) and 21.2 % both soft drinks and coffee tea caffeine beverages Conclusion: Over half of this sample of school-age Chilean children slept less than the recommended (>= 10 hours) amount, with obese participants sleeping less than normal weight subjects. The intake of caffeine products in particular, caffeinated soft drinks, was higher during the night in both groups.