1.0 Introduction The most effective strategy to improve manpower productivity is to devout resources for its development. Manpower is an important asset organization can leverage on for success and gain competitive edge in the turbulence environment in which the organization operates. Human resources is a key player in actualization of organization goals, it combine others resources together to achieve organizational set goals. Development of the organizational manpower is a dynamic and evolving practice used to enhance organizational performance. Manpower development focused on turning out human resource that is needed for effective performance in the organization (Drucker, 1999). It focuses on equipping employees with new techniques that will enable them to perform effectively and efficiently (Lawal, 2006). Emeti (2011) believes that performance should be measured since it helps to monitor employees and provide feedback information for management. Daleney and Huselid (1996) were of the opinion that organizational performance has to do with quality of service or product rendered, employees productivity and retention as well as the level at which the organization satisfies its customers. Bontis, Dragonetti, Jacobsen and Roos (1999) opined that, human resources of an organization have the capacity to bring innovative and creative ideas to the organization which is capable of bringing long term survival of the organization if well managed and motivated. Manpower is the basis of all resources use, it is the indispensable means of converting other resources to man kind’s use and benefits. So how well we employ and develop human resources skills is fundamental in deciding how much will accomplish as a nation, man power is plot of every human institution. The concept of manpower development emerged as a strategy to enhance the capacity of available employees in organization in order to improve performance and productivity. Agwu and Ogiriki (2014) were of the opinion that manpower development is the integrated use of training and development to improve effectiveness in organization. Different studies have been carried out to consider the effect of manpower development on organizational performance (Agwu and Ogiriki, 2014; Rizov and Croucher, 2008; Shih, Chiang and Hsu, 2006; among others). Despite the establishment of these scholars that manpower development leads to increase in productivity and performance, managers still pay little or no attention to manpower development but focus more on other resource. This practice renders organizations in Nigeria ineffective. Egwunyenga (2012), observed that lack of manpower development results into mal-administration and underperformance of the employees. Based on these assertions, it becomes pertinent to investigate the effect of manpower development. Objectives of the study a) To examine the effect career advancement has on organization performance. b) To investigate the relationship between on- the- job training and organization performance. c) To determine the effect off- the- job training has on organization performance.