The evaluation of quality in Environmental Impact Assessment (EIA) needs to give attention to at least two facets: the evaluation of the process and to the evaluation of the Environmental Impact Statement (EIS). Assessing the performance of the EIA process can be seen as measuring the effectiveness of EIA. The quality of the EIA can be measured in different ways: − A step-by-step analysis, in which each phase and its interconnections (intention, screening, scoping, EIS preparation, EIS review, and final record) are evaluated; − A holistic approach, in which the overall outcome of the EIA process is measured. We measured the quality in our project The preparation and realization of the complex evaluation of the EIA Act implementation in Slovak Republic in both ways in year 1998. The first approach was carried out in the form of filling in a form (in number of 150 projects), which gave us an overview of the step-by-step analysis. The second approach was done in the form of questionnaires that were sent to 30 experts.