The Korean species of Cotachena were reviewed, based on morphological characters and DNA barcodes. Our study recognized three species of Cotachena from Korea: C. alysoni Whalley, C. brunnealis Yamanaka and C. taiwanalis Yamanaka. The latter two were new to Korea. Dubious occurrence of C. pubescens (Warren) in Korea was discussed. The 23 individuals of COI barcodes were analyzed and assigned to the eleven species of Cotachena. The DNA barcodes of C. taiwanalis and C. brunnealis were provided for the first time and their taxonomic status was discussed. Host plants of C. taiwanalis were first reported. The Korean species of Cotachena were compared to the conspecific populations from neighboring countries. Photographs of habitus and genital features were provided for the Korean Cotachena, if available, to facilitate identification.