The knowledge about the geographical distribution of Aedes patersoni Shanon and Del Ponte, Ae. scapularis (Rondani), Culex dolosus (Lynch Arribálzaga), Mansonia indubitans Dyar and Shannon, Psorophora cingulata (Fabricius), Toxorhynchites haemorrhoidalis separatus (Lynch Arribálzaga), Tx. purpureus (Theobald), Tx. theobaldi s. l. Dyar & Knab and Uranotaenia lowii Theobald in the Northwest of Argentina is extended. Likewise, they provided the first known localities for Ma. indubitans in the province of Salta and for Ae. serrato (Theobald), Ma. titillans (Walker) and Ps. ciliata (Fabricius) in the province of Jujuy. The presence of Ae. fulvithorax (Lutz), Ps. pallescens Edwards in Jujuy, Ur. pulcherrima Lynch Arribálzaga in Santiago del Estero and Anopheles pictipennis (Philippi) in Argentina, is discussed. This contribution updates the list of mosquitoes for the northwestern provinces of Argentina, increasing their numbers of species in Jujuy, La Rioja, Salta, Santiago del Estero and Tucumán to 68, 26, 102, 29 and 70 species, respectively. Additionally, information on the habitat of immature stages and the sanitary importance of the species mentioned is provided, as well as a complete list of the species present in the northwestern provinces of Argentina.