Psychology, especially Industrial-Organizational Psychology has made a significant contribution to the research and policy formulation in the areas of organizational management and business administration. Motivation research is one of the areas which owe a great deal to the efforts made by Industrial-Organizational Psychologists. The paper discusses how Industrial-Organizational Psychology has contributed to the development of motivation theories, to the application of those theories to organizational management, and to the improvement of social conditions of workforce. In doing so, reference is made to the research carried out by the author herself on these topics. Lastly, the topics in which further research is expected are proposed.