This paper serves to integrate social exchange with organisational justice and performance theory. Social exchange relationships are represented by employees’ perceptions of workplace inequity and evaluated using justice rules. Employees are expected to have in-role and extra-role behavioural responses and cognitive responses to inequity. It is theorised that behavioural and cognitive responses are moderated by the employee’s perceptions of organisational justice. Much employee performance, commitment, engagement, retention and turnover may be explained by this comprehensive model.