A list of the Tephritidae from Kakamega Forest and it environs was compiled from published records, Malaise trap, baited trap, and sweep-net collections, rearings from flowers and fruits, and examination of museum specimens. One hundred and thirty-five species are recorded, and collection information is provided for all of them. Twenty-five of these species are undescribed, or were so at the time our study began. Frugivorous Tephritidae were reared from 134 of 378 (35%) fruit collections made within the forest. Fruits of 17 of 47 plant families (36%), and 37 of the 123 plant species (30%) yielded Tephritidae. The plant families of greatest importance in the life histories of frugivorous species were the Sapotaceae, Rubiaceae, Flacourtiaceae, Rosaceae and Solanaceae, while the Asteraceae provided hosts for most of the flower-feeding species. The affinities of the Kakamega forest tephritid fauna with those of other regions, in particular the main central and western African rain forests and the East African coastal forests, are discussed.