The resistance of malaria vectors to insecticides used in vector control is a major obstacle for national malaria control programs. It is in this context that an entomological study was conducted in urban, peri-urban and rural sites in the Oyem area (Northern Gabon). This study looks at species of the An. gambiae complex and the resistance mechanisms developed by Anopheles to escape to insecticides in Oyem, northern Gabon. To this end, Anopheles larvae were collected in the above-mentioned areas and reared to the adult stage in the field laboratory. Subsequently, the adult anopheles were subjected to sensitivity tests following the World Health Organization protocol. Seven insecticides (DDT 4%, Deltamethrin 0.05%, Permethrin 0.75%, Lambda-cyhalothrin 0.05%, Cyfluthrin 0.15%, Bendiocarb 0.1% and Malathion 5%) were used for these bioassays. The mosquitoes tested (live and dead) were analyzed using PCR to identify the species of the An. gambiae complex. The results obtained showed that the species Anopheles gambiae, the only species identified, has resistance to dichlorodiphenyltrichloroethane (DDT 4%) and Pyrethroids. However, this species is sensitive to Bendiocarb 0.1% and Malathion 5%. These statuses are confirmed by the presence of Kdr mutations (East and West) and the absence of the Ace-1R mutation in this vector.