Abstract: Construction delays are occurring in every phase of a project and are common problems in the construction industry. Delay in a construction project is defined as the time overrun beyond the agreed completion time specified in a contract for the delivery of a project. Delays can be minimized only when their causes are identified and analyzed. The objective of this study was to investigate the cause of delay in building construction of Ethiopia's higher education. This study was carried out based on a literature review, a questionnaire survey and a case study to collect data on delay. A total of 60 questionnaire surveys were distributed and 51 questionnaires were collected from construction professionals. The 76 delay factors compiled through the literature review and classified into eight groups (owner, contractor, consultant, early planning and design, manpower, materials, equipment and external factors). In addition, the ranking of the 76 factors was carried out to identify the most crucial causes of delay. Data was collected and analyzed using the Importance Index (II) and Statistical Package for Social Science (SPSS), whereby the score with the highest II is one that mostly influences the delay. Furthermore, case studies of 91 completed and ongoing construction projects were investigated. The results revealed the top main significant factors that contributed to causes of delay in building construction project for Ethiopia higher education are Rise in the prices of material, shortage of required materials, poor economic conditions (currency, inflation rate, etc.), delay in material delivering, financial problems (delayed payments financial difficulties and economic problems), difficulties in financing project by contractor, Political instability (Conflict, war and public energy), referral of bid to the lowest price, poor design and delay in the preparation of drawings and Improper project feasibility study. The case study result shows that in Ethiopia higher education only 3.85% of projects have been finished to the originally targeted completion date and 7.69% projects to the original targeted completion Budget. The remaining 96.15% project delayed up to 500% of its contractual time and 92.31% project delayed up to 189.14% of its contractual Budget. The ongoing project also has delay 25.64% original targeted completion Budget and 66.67% contractual time. This paper finally came up with solutions and recommendations towards reducing the impact of delays on construction projects in Ethiopia to help all contracting parties and the concerned body.