A review of present information on the zoogeography of Chironomidae at subfamily and generic levels is given. The known distribution, including some previously unpublished records, of all recognisable genera (307) and subgenera (56) is tabulated according to zoogeographical region. The greatest number of genera is known from the Nearctic (202) followed by the Palaearctic (187), Neotropical (109), Australasian (107), Afrotropical (104) and Oriental (100). The chironomid fauna of each zoogeographical region is discussed and a comparison of the number of known species and percentage representation of each subfamily for each region is given. An account of the distribution and ecology of each of the ten subfamilies is included. To date, some 3 700 species are described representing only 30 % of the estimated world chironomid fauna. The fossil record of the group is briefly discussed and the Chironomidae are estimated to be at least 200 million years old dating back to the Triassic period.