This study mainly sought to determine the effectiveness of the Open Performance Review and Appraisal System (OPRAS) on Teachers' work performance in the selected secondary schools of Vwawa, Iyula and Msangano in Mbozi district council. The study was also driven by the following main objective, which includes; how the practice of OPRAS has improved the work performance of secondary school teachers in Mbozi district council. A mixed research approach both qualitative and quantitative approach with 93 respondents was employed. Questionnaires and interviews were used to obtain data. Quantitative data was analyzed through descriptive statistics where inferences were presented in the form of frequencies and percentiles. Qualitative information was also analyzed through thematic and content analysis and presented in the form of concepts and narrations. Although Mbozi district has been effectively implementing OPRAS for the past 15 years, active data show that the district has a stable progression performance rate of 30.1 % since 2018 to date. The key variable that was tested was increased teacher commitment. Considerably, this has been established due to constant growth rates of indicators of performance against the performance of teachers from 2018 to 2023. The study recommended that the government should set and engage a realistic budget for training, and empowerment workshops and highly capacitate the Office of the public communications for the purpose of intensifying communication and feedback in public organizations including secondary schools