Dissertation (MA Public Administration)Managing performance is very important aspect in any organization in Tanzania. To improve performance in July 2004 the government introduced the OPRAS which replaced the former confidential report system of evaluating workers. This study generally assessed the influence of the Open Performance Review and Appraisal System in the performance of workers. It examined the benefits accrued from the implementation of OPRAS. Lastly it examined the extent the system helps the organization to accomplish its goals to achieve the set objectives. Both stratified random and purposive sampling was used to select 88 representative samples from Misungwi District Council. Specifically in the human resource, finance, education etc. The collected data was analyzed by using SPSS computer software. The results indicated that OPRAS is a good system which helps to improve workers‟ efficiency. OPRAS play a very important role in job promotions of workers and a minor role in training of employees and salary increments. The results indicated managers face challenges of poor accountability of employees; and the absence of valid answers from the employees. Also the results indicated that the main challenge facing subordinates is the absence of feedback and biasness. Therefore the study recommends that the government should put more emphasis on the implementation of the system by encouraging managers to effectively implement the operation of the system. For an employee to be promoted he or she must fill in this forms and assessed by the manager on his performance to insure service delivery.