Abstract: Competence-Based- Education and Curriculum (CBC) is a leading paradigm for innovative teaching and learning processes today. This paper investigated the Implementation of Competence-Based Curriculum in Enhancing Teachers' Job Performance in Public Secondary Schools in Magu District, Tanzania. It specifically intended to examine teachers’ practices in the implementation of Competence-Based Curriculum, establish the challenges that teachers face in the implementation of Competence-Based Curriculum and identify possible strategies that can be used by teachers to address the challenges encountered. The study employed the constructivism theory and utilized a mixed research approach, guided by the convergent parallel design. A sample of 100 respondents, including the District Secondary Education Officer, The District Officials, public secondary school teachers, ward education coordinators, heads of schools and public secondary school students who were chosen using simple random, snowball and purposive sampling techniques. Questionnaires and interviews were used in data collection. The quantitative data were analyzed using descriptive statistics with the aid of SPSS version 20 while qualitative data were analyzed using thematic analysis. The study presented challenges that impede teachers’ successful use of CBC and interactive teaching and learning approaches. These included lack of in-service trainings, seminars, and workshops, teachers' fear of failing to complete the syllabus, teacher certification, competency, rigidity of timetable, and a generally overloaded work and curricula. It recommended a supply adequate materials in schools , in-service teacher training , teachers’ and students’ dedication to teaching and learning and teachers improvisation of teaching and learning aids. These findings can lead to various opportunities, including the provision of CBC pedagogy training to teachers to improve their understanding of CBC and enhance its implementation. Key words: Competence-based curriculum, job performance, standards, pedagogies