Published mosquito records for Thailand listed in the world mosquito catalog and supplements and in several recently published checklists are reviewed and revised based upon specimens deposited in the National Museum Natural History, Washington, DC, USA, and the Department of Medical Entomology, Armed Forces Research Institute of Medical Sciences, Bangkok, Thailand. A total of 410 valid species/subspecies are considered valid records for Thailand. This represents 63 more species/subspecies than listed in the world mosquito catalog and supplements, and 32 more valid species/subspecies than given in the most recent published checklist for Thailand. Numerous older species records were re-evaluated for possible inclusion in the list. Distribution and collection data are provided for the new records, with notes on the location of the specimens. Notes and distribution extensions are also provided for 34 important or rarely collected species already known from Thailand. Five subspecies are elevated to species: Anopheles baileyi, An. nilgiricus, An. paraliae, Aedes greenii and Ae. leonis. Three species/subspecies are synonymized: Aedes albotaeniatus mikiranus, Ae. greenii kanaranus and Ae. hegneri. The distributions of 8 species are restricted to specific areas outside Thailand: Anopheles aitkenii to India and Sri Lanka; An. filipinae to the Philippines; An. nilgiricus to southern India; Aedes aureostriatus to eastern Indonesia and the New Guinea area; Ae. macdougalli to Southern India and Sri Lanka; Ae. niveus to the Philippines; Uranotaenia maculipleura to Malaysia and Ur. recondita to southwestern India. A total of 164 references were used in decision making and are cited to assist readers.