The main objectives of the research are to identify and rank critical success factors (CSFs) and assess their practice in implementing PPP power projects in Ethiopia. Mixed research approach were used, accordingly Questionnaires and Interview were the main data collection instruments. Intensive literature review was made to identify CSFs. The study identified and ranked 22 CSFs in power sector as it is appropriate to Ethiopia. The most important are appropriate risk allocation and risk sharing, government guarantee for revenue and convertibility, proper & adequate project feasibility studies, appropriate project identification and screening, favorable legal framework, effective, efficient, competitive & transparent procurement process and stable political, social and economic environment. Moreover, the research has assessed the practice of some of the CSFs in implementing PPP power projects in Ethiopia and found that there is a good practice towards presence of clear legal framework, availability of transparent procurement process, conducting detail and adequate feasibility studies before tendering the projects while the practice of risk identification, allocation and management, identification & management of stakeholders, convertibility risk guarantees and adequate awareness about PPP by all relevant decision makers has to be improved. Based on the findings of the research, the following are recommended: PPP power projects procuring party, implementing parties, policy maker and other relevant stakeholders shall give due attention to the critical success factors identified and ranked in their order of importance while implementing PPP projects to realize the success of the projects.