An experimental study was carried out to compare the effects of deductive and guided inductive approaches of grammar teaching on randomly grouped students in Sekota College of Teachers Education, Ethiopia. The researcher hypothesized that there will not be a significant difference between the deductive and guided inductive approaches of teaching grammar on students’ grammar achievement. A total of 46 randomly selected volunteer first year linear students were randomly placed into two groups: Deductive Group (DG), Guided Inductive Group (GIG) each of which consists of 23 students. Then pre-test was administered before the actual treatment. Then both the DG and GIG were taught about passive of English language through deductive approach in P-P-P model and guided inductive approach using PACE model respectively lasting for 3 weeks (9 contact hours each). Then the data was analyzed through t-test. (Using SPSS Version 25). The findings revealed that t-test result of the pre-test revealed that there is no significant difference between the Deductive Group (DG) and the Guided Inductive Group (GIG). Whereas the t-test result of the post-test signaled that the learner-centered Guided Inductive Approach could be more effective than the traditional Deductive Approach to the teaching of English passive voices.