In the province of Chaco, native forests cover five million hectares approximately, but over-exploitation of these forests has caused an alarming decrease in the participation of commercially important species. This project evaluated a technique for enrichment in a parcel of forest of humid Chaco that was heavily exploited during last century until the '30s and with some mild extractions after that. At the moment of establishing the evaluation, the woodland had 17 m² of basal area. The survival of planted individuals, the competence situation in which they were developing and their growth in height and diameter were assessed. Six years after planting, findings showed that only in the case of Peltophorum dubium surviving results were good and that the level of growth, both in diameter and in height, was low because the plants of enrichment grew under strong competence. The individuals under specific situations of minor competence marked differences in growth, compared with the rest.