A malária é uma doença de grande impacto na saúde pública, em diferentes regiões do mundo, inclusive no Brasil. O mosquito anofelino é vetor dos protozoários que causam a doença, constituindo parte fundamental na transmissão. O sistema imune dos mosquitos apresenta função essencial no que determina a competência vetorial desses insetos, sendo, portanto, alvo importante para estudos sobre vacinas de bloqueio de transmissão e de genes para o desenvolvimento de mosquitos transgênicos refratários ao plasmódio. Em Anopheles gambiae, vários genes foram descritos e caracterizados quanto à resposta contra os protozoários causadores da malária. Entre esses genes, o codificador da FBN9 (uma imunolectina da família dos fibrinogênios) e das proteínas da família Tep (Thioester containing protein) apresentaram resultados interessantes que demonstram uma resposta contra Plasmodium spp. e outros microorganismos. No entanto, os estudos sobre a imunidade dos vetores brasileiros, bem como sobre a resposta à infecção por Plasmodium vivax, são escassos. Neste contexto, este trabalho teve como objetivo estudar os genes FBN9 e Tep1, por meio da amplificação, seqüenciamento, análises das seqüências e da filogenia dos genes e ainda pela quantificação da expressão destes genes em mosquitos infectados com P. vivax.Malaria is one of the major public health problems in the wor ld, including Brazil. Anopheline mosquitoes are the vectors of the parasites responsible for hum an malaria. Mosquitoes have developed efficient immune responses against malaria parasit es. The mosquito`s immune system presents an essential part determining the vectorial competence to plasmodia, being an important target for developing alternative approaches for controlling malaria, such as transmission blocking vaccines and transgenic mosquitoes to block malaria parasites. Many anti-malaria immunity genes were already studied in Anopheles gambiae, and FBN9 and TEPs (Thioester Containing Proteins) have been described as important candidates, especially against Plasmodium spp. Since most mosquito immunity research focus on malaria vectors which are not present in Brazil, this project aimed to study the immune-related genes FBN9 and TEPs of Brazilian mosquitoes by amplifying, sequencing, analyzing the gene’s phylogeny and quantifying the mRNA expression on infected mosquitoes with Plasmodium vivax. FBN9 and two proteins from the Tep family (Tep1 and TepX) were identified and the partial sequences were obtained in Anopheles aquasalis, Anopheles darling, Anopheles albitarsis and Anopheles nuneztovari. The analyses showed high conservation between these proteins in the different species, presenting a large number of synonymous substitutions, suggesting that these proteins should have important structure and/or function. The phylogeny tree from FBN9 showed Brazilian anophelines and African anophelines in two separated groups. The expression analyses placed that Tep1 is 4.7 fold more expressed in carcasses from infected P. vivax mosquitoes and TepX, despite not presenting relevant difference between the expression in carcass, in midguts it is 6.5 times more expressed in infected mosquitoes. These results demonstrate that FBN9 and TepX have high evidences to have an important role in the mosquito immune response against P. vivax. Further studies, such as silencing of these proteins, are essential to have solid conclusive information.