Buk-Vlaka is located in the City of Opuzen, in Dubrovnik-Neretva County at an elevation of 2 meters above sea level and it covers the area of 5.02 km² (1.94 sq. miles). According to the 2011 census report, there were 494 inhabitants. It is predominantly populated by Croats (99%), but also. Nearby places: Vlaka, Pržinovac, Tuštevac, Mihalj, Lučina, Podgradina, Pižinovac, Otok, Trn and Opuzen.