The commonly used and developing engineering environmental technologies do not remain neutral for an ecosystem. The deepening climate changes are generally considered as the effects of human activities. There is thus no doubt that any human interference in the environment should be comprehensively checked at the beginning for all its positive and negative aspects for the environment as well as society health. There are two different analytical tools useful in environmental management: life cycle assessment (LCA) and risk assessment (RA). The first follows the product from “from birth to the grave” summing the environmental impact at all stages of its “life” including such elements like producing, used electricity, transport and many others. LCA refers to quantification and classification of all effects at all life stages and provides direct and indirect possible environmental interactions. On the other hand, risk assessment focuses on linking stressors and its possibilities and severity. RA tools reveal environmental and human health impacts of strictly separated elements, providing insight as to which emission consists of an important threat. This paper is focused on summarizing two the most used methods and tools for supporting the decision making process in use of environmental engineering technologies. In this paper, the fundamental differences between LCA and RA and benefits from their use has been contained.