Purpose: The purpose of this study is to investigate the comparative effect of transformational and servant leadership and to determine incremental variance that servant leadership can explain in employee innovative behaviour above and beyond transformational leadership. This research also examines the competing mechanisms by which transformational and servant leadership influence innovative behaviour. Design/methodology/approach: The data were gathered from 338 employees working in information technology firms of Pakistan and the proposed relationships were tested through partial least squares technique using SmartPLS software. Findings: The results reveal that servant leadership not only exerts stronger influence on innovative behaviour, but also explains an incremental variance in innovative behaviour above and beyond transformational leadership. The findings further indicate that the impact of transformational leadership on innovative behaviour is better transmitted by affective commitment. On the contrary, the impact of servant leadership is better translated through creative self-efficacy. Practical implications: This research unravels the role of transformational and servant leadership in fostering innovative behaviour in knowledge-intensive organizations. Findings of this investigation also suggest that by following a two-pronged leadership strategy, managers can augment innovative behaviour by enhancing employees' creative self-efficacy and affective commitment. Originality/value: This research provides initial empirical evidence regarding the incremental variance that servant leadership can explain in innovative behaviour above and beyond transformational leadership. Moreover, this research adds to leadership and innovation literature by unravelling the comparative effects of these two forms of leadership on innovative behaviour through theory-driven competing mechanisms.