Trends in nutritional status were studied in children born in 1993 in the city of Pelotas, Rio Grande do Sul State, Brazil. During that year, all infants born in the city were identified, and a sub-sample of 1,273 children was visited twice at home for anthropometric examinations at an average age of 12 and 54 months, respectively. Approximately 10% of all children were lost to follow up from birth to 4 years. The prevalence of nutritional deficit decreased, while that of overweight increased between ages 1 and 4 years. The prevalence of nutritional deficit showed an inverse association with birth weight, while overweight showed a direct relationship. About 50% of the children with height/age deficit at 12 months remained in this same condition at 4 years old, while a third of overweight children remained in this condition during the same period. On the other hand, some 10% of non-overweight children became overweight between 1 and 4 years of age. The nutritional transition observed in Pelotas requires a paradigm shift in health services, which are still concentrated on detecting and treating malnutrition rather than obesity.