Myelochroa (Asahina) Elix & Hale is a common foliose lichen genus found on the Korean Peninsula. Since it was first recorded nearly two decades ago, no detailed taxonomic or revisionary study of the genus has been conducted. Thus, the current study was conducted to carry out a detailed taxonomic and revisionary study of Myelochroa in South Korea. This study was based on specimens deposited in the Korean Lichen Research Institute (KoLRI). Detailed taxonomic studies and a literature review confirmed the presence of twelve species of Myelochroa from S. Korea, including one new record, Myelochroa xantholepis (Mont. & Bosch) Elix & Hale. Descriptions of each species with their morphological, anatomical and chemical characters together with a key to all known Myelochroa species are presented.