During the period from February 2009 to September 2010, a mosquito (Diptera: Culicidae) survey was conducted in Jazan province the southwestern Region of Saudi Arabia,. A total of 29414 larval and 484 adult mosquitoes were collected from 41 sites, resembling 10 governorates. The collected mosquitoes related to 7 genera and 16 species. The genera were Aedes (A.) (1 species),Stegomyia (St.) (1 species), Aedimorphus (Am.) (1 species), Anopheles (An.) (4 species), Lutzia (L.) (1 species), Culex (Cx.) (7 species), and Culliseta (Cs.) (1species) and the mosquitoes species encountered were A. caspius Pallas, St. aegypti Linnaeus, Am. vexans arabiensis Patton, An. d'thali Patton, An. pretoriensis Theobald,  An. Arabiensis Patton, An. turkhudi Liston, L. (Metalutzia) tigripes de Grandpre & de Charmoy, Cx. sitiens Wiedmann, Cx. decens Theobald, Cx.  bitaeniorhynchus Giles, Cx. pipiens Linnaeus, Cx. quinquefasciatus Say, Cx. sinaiticus Kirkpatrick, Cx. tritaeniorhynchus Giles,  and Cs.  longiareolata Macquart. Cx. pipiens is the most prevalent species in Jazan region. It was encountered in 90 % of total collection sites. Cx. tritaeniorhynchus is less prevalent encountering in 80 % of total collection sites but An. Arabinesis was encountered in 70 % of total  collection sites. St. aegypti, L. (Metalutzia) tigripes and Cx. sitiens were encountered in 50% of total collection sites. Cx. quinquefascitus, Am. vexans and Cs. longiareolata were encountered in 40 %, 30% and 20% of total collection, sites respectively. An. pretariensis, An. d'thuli, An. turkdi, Cx. decens, A. caspius and Cx. bitaeniorhynchus were the least prevalent mosquitoes in Jazan region encountered in only 10% of total collection sites. Am. vexans was the most abundant 57 % (17121), Culicine spp. 38.2 % (11416)  , Anopheline spp. 1.5 % (433), St. aegypti 3 % (749) and each of Aedine, Lutzia and Culleseta were encountered less than 1%.