Innovative employees are important for organisational competitiveness and economic growth. However, there has been little research on innovative work behaviour (IWB) in public service organisations, particularly schools. Based on data collected from a net sample of 145 teachers, and drawing from Social Exchange and Job Demands-Resources Theories, the aim of this paper was to examine the influence of leadership, organisational commitment and organisational justice on IWB of teachers. Correlations, Steiger's z-tests, and regression analyses were used to examine the hypothesised relationships. The results suggest that both leadership and organisational justice had positive and significant effects on IWB. Contrary to expectations, organisational commitment did not relate to IWB. After disaggregating leadership and IWB into their dimensions, both transformational and contingent-reward forms of leadership positively influenced innovation (idea promotion and idea implementation); but the relationships between these two forms of leadership and creativity (idea generation) were significantly smaller. Even though the relationship between organisational justice and innovation (idea promotion and idea implementation) was higher than that between organisational justice and creativity (idea generation), the difference was only marginally statistically significant. We discuss these findings; show their managerial and theoretical implications; and outline prospects for future research.