The objective of this study was to evaluate the impact of a feeding supplementation program on the growth of undernourished children younger than 5 years in the city of Guariba, state of São Paulo, Brazil. The sample consisted of 469 malnourished children enrolled in a feeding supplementation program sponsored by the State Health Secretariat. The children were divided into four groups according to how long they had been enrolled in the program: in group 1, the children had been enrolled for up to 12 months; in group 2, from 12 to 24 months; in group 3 from 24 to 36 months; and in group 4 the children had been enrolled for more than 35 months. Percentiles for weight/age, height/age and weight/height were calculated for each child. To assess the impact of the program, reference curves for the anthropometric profile were constructed based on expected variations in population percentiles. The changes observed in each group were analyzed statistically (McNemar). Groups 1 and 2 presented weight recovery and gains in the weight/height ratios for the most severely malnourished children; in group 3, the weight/height ratio was maintained and there was a discrete tendency towards weight recovery, which was reversed in group 4, in which the weight was again low in relation to height. The feeding supplementation program temporarily minimized severe nutritional deficiencies but was not sufficient to recover and maintain normal growth.