The nutritional impact of CONIN nutritional recovery centers must be evaluated, considering the current epidemiological situation in Chile and the new therapeutic focus giving more emphasis to ambulatory treatment.To analyze the nutritional status of children treated at traditional CONIN centers, the reason for their admission and the factors associated with changes of weight for age index during the hospitalization.During the year 2000, the records of 561 patients discharged from the traditional CONIN centers throughout the country were retrospectively analyzed. The changes in weight and height during admission and the possible factors influencing these changes, were determined.The average lapse of stay was 3.9 months; 78% of children had concomitant diseases at admission and 18.7% required to be admitted in a general hospital. One third was admitted with normal weight or even overweight according to the weight for age index, and 31.1% was undernourished. During admission in CONIN, the number of undernourished patients was reduced by 50%, while the proportion of children with normal nutritional status increased by 15% (p < 0.001). On admission, 7.8% of children had a low height for age, evidencing a chronic undernutrition. This figure did not change on discharge. The increase of weight/age and weight/height was substantially higher in children with a greater initial deficit (p < 0.001).Admission to a CONIN center had a low nutritional impact, and a high risk of a lengthy stay. The most favorable impact could be appreciated in children that were effectively undernourished. Admissions are motivated mainly by social issues, over and above nutritional problems.