In todayâ€™s competitive business environment, most of the organizations considered thatrnsupply chain management is one of the most important management tool so as to secure competitivernadvantage. Itâ€™s obvious that sustainable improvement in operational performance of an organizationrnenable to take competitive advantage over rivals. The objective of the study is to investigate the effectrnof supply chain integration on the operational performance of Ethiopian Maintenance, Repair andrnOverhaul. The methodology of the research in which mixed quantitative and qualitative approachrnhave been employed to gather and analyze data. The study applied questionnaire survey and semistructured interview enquiries, which are adapted from the previous study and then developed byrnusing pilot study conducted with a selected team before distribution of the questionnaires. The studyrnused to survey employees and management members working in Ethiopian Maintenance, Repair andrnOverhaul. The study applied purposive sampling and respondents who have direct exposure towardsrnthe study have been selected. The quantitative data collected from 157 respondents out of 191 samplernselected; and the qualitative data gathered from four top management member. In reference to thernreviewed literature, a model includes the most commonly used categories of supply chain integrationrnthat are supplier, internal and customer integrations as independent variables; and the operationalrnperformance as a dependent variable in which the well-known dimensions that are cost, quality andrntime have been evaluated. The study used descriptive and explanatory research design; data hasrnbeen analyzed, interpreted and discussed by using applicable statistical techniques for whichrnanalytical software tool STATA has been used, and also the findings from the interview have beenrnanalyzed, discussed and summarized as well. Descriptive statistics such as frequency, percentagerndistribution, mean and standard deviation, and also multiple-linear regression has been applied tornanalyze the findings. The result of the findings indicated that positive and significant relationshiprnbetween variables of supply chain integration and the operational performance. The independentrnvariables; supplier, internal and customer integrations are correlated and positively related eachrnother, and the same is true for the dimensions of operational performance. Supplier integration hasrnthe highest effect on operational performance, then internal integration followed by customerrnintegration. The result shows supplier integration, internal integration and customer integration arernindividually useful in predicting the operational performance of Ethiopian Maintenance, Repair andrnOverhaul. Therefore, supply chain integration has a positive effect on the operational performancernof Ethiopian Maintenance, Repair and Overhaul.