Relational resources are now recognised as significant factors in workplaces and increasing attention is being given to the motivational impact of giving in addition to receiving social support. Our study builds on this work to determine the role of such relational mechanisms in work engagement, a concept that simultaneously captures drive and well-being. Data from 182 midwives from two maternity hospitals revealed a best-fit model where perceived supervisor support, social support from peers, prosocial impact on others and autonomy explained 52% of variance in work engagement. Perceived prosocial impact acted as a significant partial mediator between autonomy and work engagement. This study provides evidence for the importance of perceived prosocial impact and the role of immediate supervisors in facilitating work engagement in midwifery. Results highlight the value of relational resources and suggest their explicit inclusion in current models of work engagement.