With its more than 35 years of experience with EIA of NEPA in United States, the extensiveknowledge base of EIA could be the most suitable place for initial field of HIA to explorelessons available for. However, caution is needed as the technical differences in analysis,different policy context, and distinct professional culture between EIA and HIA might be. Thesuccesse of EIA of NEPA is the integration of environmental goals into decision makingprocess, improved planning, and increased transparency and public involvement, whereasshortcomings of it were defined as the excessive volume and complexity of EIA documents, thelimited and adversarial public involvement, the procedural process (not substantive), focus onprojects (not on policies and programs), and the limited consideration of health impacts.Integrating HIA into existing EIA process is positive in two reasons that the human health isclosely related with natural environment and EIA process is a fully established process thateffectively cuts across bureaucratic and sectoral boundaries. Also, integrating of HIA into EIAmight be a way with least resistance for the widespread use. A freestanding HIA separatedfrom EIA is desirable in terms of excessive volume of EIA documents and the procedural andlegal focus of EIA. It is needed to develop the formulated methodologies for advancing HIAwhether it is a part of or separated from EIA, and to estimate the potential values of HIA in thesubstantial society context. When possible, HIA should be established on the ways that EIAshave been used successfully.