Competency – Based Education and Training (CBET) is a leading paradigm for innovating technical and vocational education and training (TVET) today. This paper investigated the challenges facing the implementation of the CBET system in Tanzania Technical institutions. The study employed a mixed research approach which utilized an exploratory research design. The study utilized the sample of 150 teachers from the College of Business Education (CBE), Tanzania Institute of Accountancy (TIA) and the Dar Es Salaam Institute of Technology (DIT), three deputy rectors dealing with academics, nine Heads of Departments and two officials from the National Council for Technical Education (NACTE). Questionnaires, interviews, literature reviews and observation were used in order to allow for triangulation. The quantitative data were analysed using descriptive analysis like percentages, mean and standard deviation while qualitative data were analysed using content analysis. The findings reveal various challenges, including low understanding of CBET concept, lack of support facilities and resources, large number of students in classrooms, lack of motivation to some teachers due to unfavourable working conditions, and low students’ cooperation attitude. These findings led to various opportunities including, provision of CBET pedagogy training to teachers to improve their understanding on CBET and enhance its implementation. Thus, it is concluded that, competency based teaching approaches are not well implemented in Tanzanian Technical Institutions and more efforts need to be devoted to the development of teachers’ and principals’ understanding of CBET approaches.