Identity is constantly constructed and reconstructed. It may be assumed that there are six fundamental motivational goals according to which it is organized: self-esteem, self-efficacy, continuity, distinctiveness, belonging, and meaning (Vignoles, 2011). Moreover, identity is shaped by its dialogical nature (Hermans, 2003; van Halen & Janssen, 2004). The longitudinal study was conducted to examine both the motivational and the dialogical basis of identity structure dynamics. The results showed that the more the identity element was connected with a sense of continuity and the more dialogical it was, the greater the perceived centrality of this element was after two months. Furthermore, the more the identity element satisfied the self-esteem and belonging motives, the more positive was the affect ascribed to it. In the behavioral domain of identity, participants more strongly manifested those identity aspects that were earlier rated as more dialogical and satisfying the motive of belonging. The results showed that the motivational underpinnings of identity along with its dialogical nature explain changes in identity structure.