A nationwide survey of mosquito distribution in Japan was carried out in 2013 and 2014, in order to determine the current distribution of vector mosquitoes. Forty-two study sites located either in coastal or inland areas were selected from Hokkaido to Kyushu, and mosquitos were collected using CDC-like traps with 1 kg of dry ice (dry ice traps), a sweeping net and a dipper for collecting larvae. Ten dry ice traps were operated at each study site for 3 or 4 days. Larvae were collected from various bodies of water and carried to the laboratory, where they were reared until adult for species identification. The locations of the trap and larval collection sites were recorded using GPS. A total of 16,608 mosquitoes of 44 species and 11 genera were collected in this study. Adult density ranged between 0.002 and 16.51 adults/trap night among the 34 species collected by the dry ice traps. The geographical and altitudinal distributions of the mosquito species were compared. Culex tritaeniorhynchus, Cx. pipiens group, Aedes albopictus, and Cx. orientalis were distributed widely and with a relatively high density of >2 adults/trap night, suggesting that these species are of high medical importance. In Hokkaido Ae. excrucians, Culiseta nipponica, and Ae. punctor/communis were collected at relatively high densities ranging between 0.51 and 1.98 adults/trap night, and are thus considered a locally abundant species.