This study focuses on emerging adults’ personal agency, an individual feature associated with enhanced
adaptive and resilient developmental trajectories. The two objectives were to explore the role of
demographic, psychosocial risk, and relational factors in predicting personal agency and analyze whether
romantic attachment mediates the connection between parental attachment and personal agency. The sample
consisted of 607 Portuguese emerging adults aged between 18 and 30 years. Structural equation modeling
results suggest that men are more likely to exhibit higher levels of personal agency than women. Trustful
romantic relations and good paternal emotional bonds are associated with greater personal agency, while
dependent romantic relations and maternal relations, characterized by inhibition of exploration, are
associated with lower personal agency. Moreover, in romantic relations, trust, unlike dependence, partially
mediates the association between parental attachment and personal agency. These findings are discussed
based on attachment and self-determination theories, considering the importance of secure relationships for
agency and autonomy in personal actions. This study provides important evidence for the influencers and
mediators of personal agency, contributing to a better understanding of this individual capacity.