Empirical research has shown that as management control systems (MCS) put heavy pressure on managers to achieve their objectives, they may induce two types of unethical behaviour: creation of budgetary slack and data manipulation. Recently, studies have introduced Organisational Justice theory into the area of management accounting research and shown the positive effects of organisational justice on managers attitudes and behaviours. However, few studies have systematically analysed how MCS fairness reduces unethical behaviours and whic characteristics of MCS could increase managers perception that they are treated fairly. The purpose of the paper is to contribute to this research. It formulates testable hypotheses on how some specific dimensions of MCS can enhance perceived fairness, which in turn helps to reduce the creation of slack and data manipulation through increased Organisational Commitment and Trust in supervisor.