Due to its rapid growth and tolerance to varying environmental conditions, Crassostrea gigas (Thunberg, 1793) (Pacific oyster), has become one of the most important species in shellfish aquaculture. This aquaculture industry facilitated the worldwide expansion of C. gigas since the late 1990s, causing C. gigas to invade all European waters. With this contribution we present the first record of C. gigas along the Black Sea coast of Turkey. A total of 235 adult oyster specimens were collected from rocky shores in an area of about 200 m² along the northern coast of Turkey, 23 km west of Ordu city. Species identification was achieved by comparing sequences of the mitochondrial gene fragments COI and 16S. this allowed Crassostrea gigas to be distinguished from C. angulata (Lamarck, 1819) (Portuguese oyster), its closest relative, and all other Crassostrea species. Considering the size of the sampled specimens, it seems probable that Crassostrea gigas has been present in the region for at least three years. Apparently, the species has adapted to the Turkish Black Sea and has established breeding populations. Future studies will have to assess the impact of C. gigas on local native species and communities.