The elaterid beetle fauna has been thoroughly investigated on Yaku Island, one of the Ôsumi Islands, Ryukyu Islands, Japan, and many species have been added to or excluded from the fauna. However, the fauna is difficult to assess because there is discordance in the information from the distribution records. In this study, we examined specimens collected by us as well as reviewed previous records from Yaku Island understand the elaterid beetle fauna of the island. During our fieldwork, we found 43 species, but no newly recorded species. Based on references and specimen information, the distributions of four species are discussed: Rismethus ryukyuensis Ôhira, 1999, Elater niponensis (Lewis, 1894), Zorochros (Yamatostrius) osawai (Ôhira, 1972), and Paracardiophorus opacus (Lewis, 1894). Of these, E. niponensis and P. opacus are removed from the list of species occurring on the island. As a result, 95 species in 48 genera of six subfamilies have been confirmed on Yaku Island, and a checklist of these elaterid species is provided.