The assesssment and management of chemicals appears to be the basic instrument for achievement of socially and economically acceptable levels of human health and environmental risks. It is recognized that striving for a "zero risk" level (complete elimination of particular chemicals) is not always necessary to attain the environmental protection goals. While the methodology of human health risk assessment has nowadays a solid framework based on the approach introduced by US EPA in eighties, the identification and evaluation of environmental risks is undergoing an intense development worldwide. The basic steps of this process - hazard identification, dose - response relationship, exposure evaluation, and risk characterization - are virtually identical with those used in human health risk assessment, but the overwhelming complexity of the subject creates many differences and difficulties in attempt to reach a unified methodology. The current state-of-art is given and some fundamental aspects on individual phases are briefly discussed.