A Dissertation Submitted in Partial Fulfillment of the Requirements for the Award of the Degree of Master of Public Administration (MPA) of Mzumbe University.This study examined challenges facing the implementation of OPRAS as a tool for measuring performance in Public sector organizations so as to ensure efficiency and effectiveness in service delivery to the public. The specific objectives of this study were to examine how OPRAS is operationalized and implemented in local government authorities; to assess the perception of LGAs’ employees on the implementation of OPRAS; to examine existing challenges in implementing OPRAS in local government Authorities; and to come up with constructive recommendations/solutions, suggestions in improving OPRAS. The case study research design was used whereby Butiama District Council was selected as a focus of the study. Both primary and secondary data were collected through the use of different data collection methods such as interviews, questionnaires and documentary review and lastly analysis of the collected data was done. The findings of the study revealed that OPRAS does not work as intended due to the following factors: its modalities of measuring performance; the poor implementation of the feedback mechanism; and local government workers’ experience of not seeing any tangible benefits/results out of the implementation of OPRAS. Furthermore, the findings of this study show that there is lack of skills among users of OPRAS and incompetent appraisers due to limited or lack of training, poor focus of the trainers during training session’s hence poor ability and willingness of the appraisers to assess and evaluate their subordinates fairly and accordingly. Based on these findings, the study recommended that commitment should be encouraged to all employees involved in the local government. Very specifically, experienced individuals should take the lead in the implementation of OPRAS in the local government authority. Essentially, it is necessary to seek or secure top-level management support in order to obtain an adequate commitment of time and resources for the performance management system