This study aimed at investigating the implementation of competence-based curriculum in certificate teachers colleges in Tanzania. The study employed a comparative case design between two teachers colleges (public and private) located in Mbeya region of Tanzania. In order to achieve the study objective, two research questions were formulated. One: What is the knowledge of teacher educators concerning competence-based teaching approaches? Two: To what extent can teacher educators practice competence-based teaching approaches in teaching the subject of geography? The study was guided by the Stufflebeam model and the theory of curriculum implementation. The study was qualitative in nature and employed qualitative data collection methods, comprising interviews, focus group discussions, classroom observation and review of documents. The study involved four teacher educators, twelve student teachers, two College Principals and one Curriculum Developer. These participants were deliberately selected, amounting to a total number of nineteen. Gender balance was observed in the selection. In this study the findings indicated that teacher educators in public teachers college demonstrated a high level of academic qualification than their counter parts in private teacher college. Also teacher educators in both colleges showed that they were knowledgeable on participatory methods but the practice in the classroom was dominated by non-participatory methods contrary to the suggested competence-based teaching approaches. Observed challenges from both teacher colleges were shortage of teacher educators, overcrowded classes, in adequate teaching and learning resources and short time for teaching practice. The study concludes that Competence-based curriculum was not implemented as it was intended at the classroom level. This phenomenon shows that policy makers have to consider the classroom reality in order to effectively reform teacher education curriculum by providing in-service training to teacher educators. Also the enrolment of student teachers have to consider the capacity of college in terms of availability of teaching and learning resources and number of teacher educators with qualified qualifications.