A mixed research design is employed to assess the roles of cluster supervision in improving primary education curriculum. To conduct the study survey design was employed by taking sample wereda, cluster centers, teachers and principals randomly and interview was conducted to support the quantitative data findings. Hence, the main findings emerged from this study were: benefits teachers gained from cluster supervisors practice was insignificant; cluster supervisors and principals are ineffective in creating favorable situations for teachers to get in-service education; school visits by cluster supervisors and principals were irregular. Finally it recommended to arrange short-term refresher training and discussion forums; participate in decision-making process related to curriculum at all stages and the cluster supervisors should coordinate different groups of implementation and improvement of the curriculum. Moreover, the regional education offices, the zone education department, or the school should give orientation about the role and responsibilities of the cluster supervisors and allocates budget for school cluster supervision.