Short descriptions of the females and males of all the species of the bee genus Halictus Latreille, 1804 (Halictidae) known from Turkey are given. Dorsal and lateral views of the male genitalia of 18 species were photographed by scanning electron microscope and 12 species by digital camera systems. The morphological differences in the male genitalia are discussed. The female of Halictus (Monilapis) pentheri Bluthgen, 1923 is described for the first time. The West Palaearctic distributions of Halictus species were evaluated. A comparison of regional richness and diversities of the fauna revealed that the Halictus fauna of Turkey constitutes 47% of West Palaearctic elements with 35 species. The Mediterranean region, Middle East and Turkey were established as high diversity regions for Halictus.