The purpose of this study was to assess school leadership effectiveness on students’rnacademic achievement in terms of leaders’ instructional leadership roles and leadershiprnstyles and to see factors affecting their effectiveness in the secondary schools of JimmarnZone. The study employed a descriptive survey research design and quantitative andrnqualitative research methods. Among 18 weredas in the zone, 4 were selected by simplernrandom sampling technique and all of the (8) secondary schools in those weredas werernincluded as a sample. Data for the study were collected through questionnaires,rninterviews, and document analyses. Questionnaires were prepared and administered torn86 teachers selected by using simple random sampling techniques and 51 school leaders.rnAll principals were interviewed and the analyses of necessary documents were made inrnall sample secondary schools. The data collected were analyzed by using percentages,rnmeans, and weighted means and an independent sample t-test used by computing the datarnon SPSS version 16. The data gathered through open ended questions, interviews andrndocument analyses were analyzed qualitatively through narration for the purpose ofrntriangulation. Finally, the findings of this study revealed that there is an insignificantrnschool leadership roles played as an instructional leaders for students’ academicrnachievement; moderate commitment of school leadership to influence students’rnachievement; poor performance of students’ academic achievement and moderaternpractice of the three (democrat, lasses-faire, and authoritative) with a dominant use ofrnauthoritative leadership style used by school leaders. Furthermore, lack of training, lackrnof regular support, unavailability of educational resources and principals’ role diversityrnare among the major factors that hinder school leadership effectiveness. Generally, fromrnthe findings of the study, it was concluded that school leaders are not effectively playingrntheir leadership roles as instructional leaders due to limitations of capacity and otherrnresource constraints found in the school. Therefore, it was recommended that ZonernEducation Offices and the Regional Education Bureau should build the leadershiprncapacities of the school leaders by providing necessary leadership training and technical,rnmaterial and professional support to secondary schools. School leaders should also bernstrongly committed to having instructional leadership roles and use more of therncombination of the three leadership styles depending on the situation as they are neededrnthan the dominance use of a single leadership style in their school administration.