A taxonomic study of Korean Notothecta Thomson is presented. Two species are recognized [N. effecta (Sawada) and N. watanabei (Sawada)] and a new synonym, Atheta (Atheta) taesongsanensis Paśnik = N. watanabei (Sawada), is proposed. Notothecta effecta is reported for the first time in the Korean peninsula. A key and illustrations of diagnostic characters are provided.