Commentators have argued that the traditional organizational career, viewed as a classic example of a mutually beneficial relational exchange between employers and employees is no longer viable nor desirable in a context of a turbulent competitive landscape and changes in individual work values. An alternative, characterized as protean and the boundaryless, presents the career unfolding across organizational boundaries and driven by individual values and agency. Research has explored its consequences for individuals and organizations while largely ignoring its key antecedents. Our paper addresses this omission by exploring the role of three key antecedents - core self-evaluations, social capital and perceived employability – which are discussed in the literature as relevant shapers of sustainable contemporary careers. Our longitudinal study, following a cohort of university students transitioning into the labour market, supports the role of these antecedents in shaping new career orientations.