Environmental Impact Assessment (EIA) is a systematic process that proactively examines the potential consequences of development actions. As a planning process, the longer-term objective of EIA is to contribute to sustainable development. In Ethiopia, EIA is now become a legal requirement and the system has been established. Even though the legal framework and institutional setup are in place to run the system, it is not yet well implemented to help achieving environmentally friendly developments.rnThis specific study has aimed to evaluate the status of EIA implementation in dam projects. Two dams from Oromia and Amhara National Regional States were selected as case study to undertake the research. The evaluation was based on the assessment of adequacy of EIA legislation, EIA administration, EIA procedure, implementation of EIA recommended measures, public participation and quality of EIS. The study was carried out through questionnaire, interview, analysis of project specific documents, focus group discussion and field observation.rnThe research has identified that the current EIA practice in dam projects is not effective enough to meet the intended objective. The factors affecting the effectiveness are absence of law enforcement tools (regulation and directives), absence of EIA system monitoring, weak regulatory enforcement, lack of legal requirements for specific components, poor integration of EIA into decision making process, lack of public involvement, weak integration of EIA into project cycle, poorly developed environmental database and information system, quality of EIA reports and weak inter-sectoral coordination and communication and limited physical and human resource availability. In order to improve its efficiency and effectiveness, particular emphasis need to be given to deficiencies in EIA legislation, omission in key stages and components of EIA process, organizational capacity of environmental protection organs, database and environmental information system, participation of local communities and organizations, defining sectoral responsibilities, awareness creation to different actors involving in the EIA process and monitoring and follow up.rnKey words: Dam, EIA, EIS, environmental management plan, Ethiopia, impact, implementation and follow up, public participation