Although considerable research has focused on employee reactions to organizational justice, far less research has examined why managers adhere to rules of justice in the first place. Taking a proactive approach to organizational justice, we address this void by examining managerial motives for adhering to distributive, procedural, informational, and interpersonal rules of justice on a day-to-day basis. Results of an experience-sampling study of 90 managers who completed daily surveys over a three-week period revealed that both "cold" cognitive (i.e., effecting compliance, identity maintenance, and establishing fairness) and "hot" affective (i.e., high positive affect and low negative affect) motives were associated with managerial adherence to justice rules. Moreover, "cold" motives were more strongly associated with justice rule adherence for justice dimensions over which managers perceive less discretion, while "hot" motives were more strongly associated with justice rule adherence for justice dimensions over which managers perceived greater discretion. We discuss the implications of our findings for both theory and practice.