Public participation in environmental impact assessment process in Latvia determines the 1998 Law "On Environmental Impact Assessment" and the relevant Cabinet of MinistersRegulations. Public participation in EIA during the development and its impact on decision-making is increasing every year, it became more active and discerning. The study of public importance and the role is based on practical experience in specific EIA projects, legislative analysis and experience of other states. Public participation in the EIA process, obviously, is a large, sometimes even determinant role in decision-making, but the practice also shows the weaknesses of public participation and involvement. This work will be discussed and analyzed the interaction between society and the EIA developers and the public and decision makers, public opinion, the clearance under the EIA method and the effectiveness of these methods, role of public opinion in the EIA report preparation process and decision-making.