Instructional leadership is essential for the academic success of any schooling situation. The purpose this study was to evaluate the instructional leadership practices employed in the primary schools of Siltie Zone, Ethiopia. Descriptive survey research design was used to conduct the research. Mixed research method was used to collect and analyze data concurrently, and triangulate results side by side. In a year 2018, a total of 228 primary schools are operating in the zone, off these, 74 primary schools were selected as target population by clustering them based on ecological conditions of the zone. Finally, 19 primary schools were selected as a sample via multistage sampling technique. From these 19 primary schools: 92 teachers were selected by simple random sample technique, and 19 school principals and 19 vice principals were also selected by availability sampling technique. In addition, 4 primary schools’ supervisors and 4 Woredas (District) heads were engaged in the study. Questionnaire and interview were used to collect data. Data was analysed by calculating mean, standard deviations P-value and t-test. Data collected by interview was narrated and triangulated with result obtained from questionnaires. The findings of the study revealed that all the three instructional leadership dimensions; defining and communicating school mission; managing curriculum and instruction and promoting a positive school learning climate were not effectively applied in the primary schools Siltie Zone, Ethiopia. The study concluded that instructional leaders in the primary schools were not effectively implementing Instructional Leadership Dimensions to improve instructional practices so as to maintain better learning for students and establish effective schools. Finally, it was recommended that tailored and continuous trainings, workshops and experiences sharing events should be organized and commenced by the respective district and zonal education officials to build the instructional leadership capacities of school leaders.