A Dissertation Submitted in Partial Fulfilment of the Requirements for Award of Master of Science in Human Resource Management of Mzumbe University.Retention of human resources has been shown to be momentous to the development and the accomplishment of the organization‘s goals and objectives. Retention of employees can be a vital source of competitive advantage for any organization. Employees today are different. They are not the ones who do not have good opportunities. As soon as they feel dissatisfied with the current employer or the job due to lack of advancement opportunities, salary and remuneration and others; they switch over to the next. The result is that employers lose their invested resources to their competitors, organization image is lost, and more over the morale of the existing staff goes down. It is, therefore very important that employers retain their employees. This study looks at the rewards practices on employee retention in The Ministry of Defense and National Service (MoDNS), from the point of view of its employees and what role of rewards plays in their job retention. A sample population of sixty employees comprising of senior and junior level staff in the various departments was used. The study confirms that lack of advancement opportunities, lack of reward and recognition and remuneration were more common reasons for departure among all employees. Retaining employees is a primary concern for many public organizations today. This study recommends that retention strategies should be aimed at retaining highly skilled personnel and at the same time building up under-performers. Feedback on employee performance is vital for building confidence in the retention practices of the Ministry of Defense and National Service. In addition, it is suggested that management should encourage their employees to take courses through distance learning, correspondence courses etc, to help improve job satisfaction. Motivation of employees produce a culture of commitment to the objectives of the organization.