Blackberry cultivation has increased its popularity in Turkey due to the use of more blackberries in Turkish cuisine. To provide farmers with well adapted blackberry cultivars, some blackberry cultivars including a Boysenberry genotype from North America has been planted to various geographical regions in Turkey. In this study, genetic diversity among these blackberry cultivars and their genetic relationship with Boysenberry and raspberry were analyzed using AFLP markers. Our results indicated that Blackberry cultivars from North America had narrow genetic background which can pose a problem for future breeding programs. Blackberry genotypes selected from Bursa province of Turkey shared all AFLP markers with the cultivar Chester, which suggests that they were not unique genotypes. Although genetic similarity between Boysenberry and blackberry was low, Boysenberry was genetically related to common blackberry cultivars. On the other hand, AFLP analysis was unable to detect any genetic relationship between Boysenberry and common raspberry cultivars from North America in this study.