Information about the Anthozoa in the Adriatic Sea has been available in the scientific literature since the second half of the 20th century. These data primarily cover the western coast and the northern and middle regions of the Adriatic, down to the city of Dubrovnik (Croatia), leaving the southeastern Adriatic (Montenegro, Albania, and the northwest waters of Greece) relatively under studied in historical research. The aim of this paper is to present new information and a checklist of Anthozoa from the southeastern Adriatic by incorporating unpublished data, data from technical reports, and any other available information source. A total of 450 Anthozoa records were compiled, including 109 new records, and the updated checklist for this area currently comprises 62 species. The most numerous species and the most numerous records belong to the subclass Hexacorallia; this pattern is consistent throughout the Adriatic. The number of Octocorallia species was almost equal in Croatia, Italy, and Montenegro (24, 20, and 20, respectively), whereas it was significantly lower in Albania (9). Two species, Pachycerianthus multiplicatus Carlgren, 1912 and Pachycerianthus solitarius (Rapp, 1829), have been reported for the first time in the southeastern Adriatic, while several species are notably rare, and seven species have been documented only once. A total of 24 protected species were identified in this area. Furthermore, some species are endangered, and necrosis incidents have been reported in Savalia savaglia (Bertoloni, 1819) colonies. Although knowledge of anthozoans in the southeastern Adriatic has significantly improved in recent years, it is important to emphasise the need for more comprehensive studies to enhance the understanding and protection of these species.