Objective: To identify the age at which ultra-processed foods are introduced in the diet of infants enrolled in public daycare centers and analyze these foods' nutritional composition according to the Traffic Light Labelling system adapted to the Brazilian norms and recommendations.Methods: Cross-sectional study including 636 nursery age children attending day care centers. Their mothers were interviewed about the age of introduction of instant noodles, snack chips, encased meat, chocolate, ice cream, and stuffed cookies. The proximate composition of these foods was evaluated according to the Traffic Light Labelling adapted to the Brazilian norms and recommendations, which classifies total fat, saturated fat, trans fat, fiber, and sodium amounts as green, yellow, or red indicators.Results: It was found that before 12 months of age 70.6% of children had consumed instant noodles, 65.9% snack chips, 54.7% encased meat, 67.1% chocolate, 36.9% ice cream, and 68.7% stuffed cookies. In addition, all foods were classified as red for saturated fat and sodium and 50.0% were classified as red for total fat.Conclusion: The introduction of ultra-processed foods in the children's diets occurred early, but it is worth mentioning that such foods have an inadequate nutritional composition, contributing to the excess consumption of total fat, saturated fat, and sodium, as well as low fiber.