The purpose of the study was to assess the school principals’ practice in curriculum implementation in Eastern Harereghe Zone. To accomplish this purpose cross-sectional descriptive survey design was employed. The study was carried out in seven randomly selected secondary schools (a total of 288 study participants) . Data were collected from teachers; PTA members, principals, vice principals and Woreda education officers through interview and questionnaire. The results of the study revealed that school principals’ leadership practices were low in promoting student learning and achievements in terms of monitoring, evaluating, coordinating and controlling teaching and learning process. Furthermore, the study revealed that inadequate professional support from concerned bodies, lack of leadership experience, lack of confidence on the part of principals to exercise leadership practice, and weak principals initiative for staff professional development are major factors that hinder proper school leadership practices in curriculum implementation. It is recommended that the ZED, WEO and other stakeholders should identify principals’ weakness in their leadership practices and provide adequate and sustainable professional guidance and support.