As part of the International Self-Identity Research Project, this study explored sources of identity among Turkish adolescents. The interview sample consisted of three male and three female high school students in Ankara, Turkey. The results indicated that social, familial, personal, physical, and moral-ethical dimensions contributed to adolescents' definitions of self, but to different degrees. Social and familial dimensions were very influential and were used as reference points for defining self in other areas. Physical and personal aspects of identity were also apparent, but were not as salient as social and familial dimensions. Patriotism and religion played a role in moral-ethical identity. Overall, self-identity influenced emotional state, cognitive and behavioral functioning, and social relations to a significant degree.