The Poecilimon ornatus group has an exclusively European distribution and includes the largest species in the genus. A revision of the taxa belonging to this group in Bulgaria and Macedonia (Central and Eastern Balkan Peninsula) is presented. Nine taxa described from Bulgaria are synonymised with 3 previously known species, as follows: Poecilimon ornatus (= P. mistshenkoi marzani, syn. n., P. mistshenkoi tinkae, syn. n., P. mistshenkoi vlachinensis, syn. n.), P. affinis s. str. (= P. mistshenkoi mistshenkoi, syn. n., P. affinis ruenensis, syn. n., P. affinis rilensis, syn. n., P. affinis medimontanus, syn. n., P. harzi, syn. n.) and P. hoelzeli (= P. kisi, syn. n.). The synonymy of P. poecilus with P. affinis and the subspecific status of P. affinis komareki are confirmed. One species, Poecilimon jablanicensis, sp. n., is described as new to science. A tabulated key, lists and maps of all known localities and oscillograms of the songs of all the species in this group are presented. The phylogenetic relationships and evolutionary trends in the Poecilimon ornatus group are discussed.