This study investigated on Constructivist Classrooms and their Impact on students’ academic achievement in Geography in Secondary Schools in Bamenda Urban Municipality in Cameroon North West Region. Three specific objectives and hypotheses guided the study. The study adopted the descriptive survey design.  Eight hundred and fifty-four (854) form four students from three functional public secondary schools in Bamenda Urban Municipality constituted the population of the study. Two hundred and seventy-two (272) form four geography students were selected to form a sample of the study. Data was collected using structured questionnaire. The results show that lecture-illustrative teaching and cooperative learning methods have significantly positive effects on students’ academic achievement in Geography as indicated by a p values of 0.000. Also our findings show that the discussion teaching method has no significant positive effect on students’ academic achievement in Geography as indicated by a p value of 0.065. We therefore conclude that constructivist classrooms improve students’ academic achievement in geography. It is therefore, recommended that geography teachers should use diverse teaching methods to teach lessons in geography in order to improve students’ academic achievement.