This study is on teacher trainers and teacher trainees' perceptions and practices of active learning and the constraints to implementing them in the English Department of Bahir Dar University. A mixed study approach that involves a quantitative self administered questionnaire, a semi-structured lesson observation guide, and qualitative in depth interviews was used to obtain relevant data. Information on what perceptions and attitudes teacher trainers and teacher trainees' hold towards active learning, how often they use such methods, and what factors constrain teacher trainers from implementing active learning methods are obtained through the questionnaire. In-depth interview of teacher trainers and classroom lessons observation were used to extrapolate the subjects' responses from the questionnaire. The findings indicated that both teacher trainers and teacher trainees employed Active learning. Teacher trainers used pair and group work more than they use other active learning methods. Teacher trainees on the other hand used more group work, reflection and whole class discussion. No statistically significant difference was noted in the perceptions of teacher trainers and trainees towards active learning. Overall, the study results indicated that there was a shift from the traditional teacher fronted lecture to student centred active learning, which is desirable. While the study findings indicate that both teacher educators and trainee teachers have positive perceptions towards Active Learning, the particular methods they use in their classroom tended to be dictated by the peculiarities of the classroom contexts they work in. The findings point towards a need among teacher practitioners to make informed decisions in choosing active learning methods that suit the specific realities of the classroom they work in. The findings have implications to teacher trainers at the university and trainee teachers working in high schools.