Mosquito collections were carried out for a period of one year from January to December 1992 in a pig farm in Sungai Pelek, Selangor, Malaysia. A total of 41,022 mosquitos belonging to 52 species and 20 genera were collected. Culex tritaeniorhynchus and Cx. gelidus, the important vectors, comprised 63% of all mosquitos collected. Both these species were collected in large numbers during the wet months of May and December. The other predominant species in that area were Cx. fuscocephala, Cx. quinquefasciatus, Cx. sitiens, Aedes butleri, and Armigeres subalbatus.