This study aims at studying mosquito-borne diseases as the major public health threat in Iran. Sanandaj outskirts are considered suitable habitats for mosquito larvae. In view of scanty reports on mosquito-borne disease implementation in this area, a study was undertaken to determine the mosquito fauna and frequency of mosquito larvae at Sanandaj City.In order to study the mosquito (Diptera: Culicidae) fauna, the samples were collected from May to July 2009 using dipping and night catch methods in Sanandaj district, Kurdistan province, western Iran.Three genera and 11 species of the Culicinae subfamily were identified--Aedes vexans Meigen, Ochlerotatus caspius s.l. Pallas (indicating new occurrence records for the province), Culex hortensis Ficalbi, Cx. pipiens Linnaeus, Cx. mimeticus Noe, Cx. theileri Theobald, Culiseta longiareolata Macquart, and Cs. subochrea Edwards.Present study revealed that Ae. vexans and Ochlerotatus caspius s.l caught had not been previously recorded in Kurdistan province, highlighting the deficient knowledge of the fauna and distribution of Culicinae mosquitoes of this part of Iran.