Attempts to isolate viruses from 178,181 unengorged female mosquitoes collected from different ecologic areas of Sri Lanka yielded 31 isolates: 17 of Japanese encephalitis (JE) virus, nine of Getah virus, three of a Batai-related bunyavirus, and two of Arkonam virus. Culex tritaeniorhynchus and Mansonia uniformis mosquitoes were found to carry JE virus in a dry zone nonepidemic area, and Cx. pseudovishnui was found to carry it in a wet zone nonepidemic area. Japanese encephalitis virus was isolated from Cx. tritaeniorhynchus, Cx. gelidus, Cx. fuscocephala, and Cx. whitmorei during a human epidemic in the dry zone. Getah virus was isolated from Cx. tritaeniorhynchus, Cx. gelidus, and Cx. fuscocephala collected in the vicinity of swine. Isolations of Getah, Arkonam, and Batai-related viruses from Sri Lanka are reported for the first time.