The existing literature has explored the role and importance of personality traits in leader prototypicality. However, limited research exists concerning the link between personality traits and leader emergence or prototypicality in ad hoc teams. Based on the relational leadership and attachment literature, we examine whether leader attachment orientations can serve as antecedents of leader prototypicality in ad hoc teams. Utilizing an ad hoc problem-solving task featuring a round-robin design in a sample of 197 participants, we find that individuals with a dominant avoidant attachment orientation were more likely to be perceived as leader-like or leader prototypical. In comparison, individuals with a dominant anxious attachment orientation were much less likely to emerge as leader prototypical. We interpret these findings in alignment with attachment theory and relational leadership and discuss the role of relational personality traits in ad hoc teams with no formally appointed leader.