PurposeProsocial job characteristics have received the least scholarly attention among the antecedents of employee innovative work behavior (IWB). Hence, antecedents' role remains largely unknown, especially in public sector organizations. Based on the relational job design theory, job characteristics theory (JCT) and public sector innovation literature, the authors examine whether job impact (JI) promotes public sector employees' IWB mediated by work meaningfulness (WM). This study also assesses whether servant leadership (SL) strengthens the influence of JI on IWB (via WM).Design/methodology/approachThe model was examined on a sample of 180 employee-supervisor dyads (90 supervisors and 180 employees) recruited from various government departments in the United Arab Emirates (UAE).FindingsThe finding supports the proposed moderated mediation model in which JI enhances IWB. The association between JI and innovative behavior via WM is found to be stronger under high SL behavior.Originality/valueThe authors' findings offer prescriptive insights into SL's crucial role in illustrating when and how JI promotes IWB and offer relevant managerial recommendations for encouraging public sector employees to demonstrate innovative behavior. The authors also provide empirical evidence on the significant contribution of a prosocial job characteristic, i.e. JI, to IWB. In addition to having theoretical and practical significance, the authors' study is aligned with the UAE National Innovation Strategy 2015.