The biological activity of organic extracts of leaves, branches and fruits of Cedrela fissilis and Cipadessa fruticosa (Meliaceae), besides stems and roots of C. fissilis was evaluated against Spodoptera frugiperda (J.E. Smith), maintained in laboratory conditions. The organic extracts (at 1000 mg kg-1) were incorporated into an artificial diet and offered to S. frugiperda during its larval period. It was evaluated the duration and the mortality of larval and pupal periods and pupae weight. The results showed that the dichromethane extract of leaves of C. fissilis was the more active one. It was observed the prolongation of the larval phase, followed by the reduced pupal weight, besides larval mortality of 63,3%.