It was evaluated the bioactivity of methanolic (F00 5) and ethanolic (F001) extracts obtained from Annona cherimolia seeds. It was made using original seeds and ungreased seeds. Brine shrimp nauplis was used as a preliminary bioassay and fourth instar of larvae of Culex quinq uefasciatus as a confirmative bioassay. The higher activity in front of fourth st age larvae of C. quinquefasciatus was exhibited by total raw ethanol ic extract of ungreased seeds (F001). The LC 50 obtained was 0,102 µg/mL in 24 hours of exposure. Chromatographic analysis by High Performance liquid chromatography (HPLC) showed 14 acetogenin compounds in the ethano lic extract, and bullatacin was probably one of them by time standar d retention.