The genus Aridelus Marshall is a cosmopolitan genus of the subfamily Euphorinae. The genus comprises about 50 species worldwide, including 11 species in the East Palaearctic Region. Korean species of the genus have been investigated by several researchers (Papp, 1992; Belokobylskij, 2000; Ku et al., 2001). The members of the genus Aridelus parasites on nymphs and adults of Pentatomid species (Shaw, 1985). In this study, Aridelus aulacocentrum is reported for the first time from Korea. Diagnosis and photographs are provided. A key to the Korean species of genus Aridelus is also given.