Organizational commitment and job satisfaction are two interrelated work attitudes, and the kind of relationship which is influenced by the economic sector and the type of employment. Employees develop commitment profiles that relate differently to job satisfaction and its facets. Furthermore, individuals experience two different regulatory foci that relate to the forms of organizational commitment, and these foci develop into separable characters that moderate the commitment/satisfaction relationship. Since commitment predicts organizational citizenship behaviours, and satisfaction relates to these behaviours, then job satisfaction mediates the relationship between organizational commitment and organizational citizenship behaviours (OCBs). Study 1 investigates the research hypotheses based on the moderating role of the economic sector in relation to job satisfaction/organizational commitment relationships, especially in regard to the forms of commitment and the facets of satisfaction – extrinsic satisfaction and intrinsic satisfaction. Overall, 618 employees successfully completed the questionnaires (258 from private sector companies and 360 from the public administration). Then, distinguishable organizational commitment profiles were developed and constructed from the forms or constructs of commitment. Two different samples are used in Study 2 in order to test the relevant hypotheses – 1,119 employees from the private sector and 476 from the public sector. Study 3 uses the concept of regulatory focus, where the two foci relate differently to forms of organizational commitment, and these two states moderate the satisfaction/commitment relationship; furthermore, individuals develop four separable regulatory focus characters based on the two major regulatory foci. Moreover, the moderating intervention is crucially influenced by the employment status of the individuals. The research hypotheses developed in this part are tested through two samples of employees: 258 working in the private sector and 263 in the public sector. Study 4 examines the mediating role of job satisfaction on the organizational commitment/organizational citizenship behaviours relationship. It argues that job satisfaction mediates the relationship between the forms of commitment and OCBs, and furthermore, job satisfaction more strongly mediates the relationship between these forms and loyal boosterism (one of the OCB dimensions). The relevant hypotheses were tested through a combined sample of 646 employees, equally drawn from the two sectors. The results are discussed, implications and contributions analyzed, and limitations and recommendations for future research presented.