Procedural justice researchers have consistently found that if authorities treat people with trust, fairness, respect and neutrality, people will not only be more willing to cooperate with authorities, but they will also be more likely to comply with authority decisions and rules. New research in this area has gone on to explore the role that emotions play in response to procedural justice and injustice. What this new research has neglected to do, however, is examine whether emotions mediate the effect of procedural justice on subsequent compliance behaviour in real life settings. Using longitudinal survey data collected in two real-life contexts (Study 1: a taxation dispute (N = 652), and Study 2: workplaces (N = 2366)), the present study will show that perceptions of procedural justice influence the emotions experienced by people, but more importantly these emotional reactions (i.e. anger and happiness) mediate the effect of justice on subsequent compliance behaviour. In other words, it is these positive and negative emotional reactions to perceived justice or injustice that go on to predict who will and will not comply with authority decisions and rules. Copyright © 2008 John Wiley & Sons, Ltd.