Life-cycle assessment is a technique to assess environmental impacts associated with all the stages of a product's life from-cradle-to-grave - from raw material extraction through materials processing, manufacture, distribution, use, repair and maintenance, and disposal or recycling. It is fairly new approach, but till now many methodologies and tools have been developed on the basis of LCA. They usually compile an inventory of relevant energy and material inputs and environmental releases, evaluate the potential impacts associated with identified inputs and releases and finally they could be used to interpret the results in order to help decision makers to make a more informed decision. Different types of methodologies are discussed in the manuscript. Generally they could be divided into different types like midpoint impact assessment methods with or without normalization and weighting or endpoint impact assessment methods as well as mixed type ones. Methodologies BEES, CML 2002, ECO-INDICATOR 99, IMPACT 2002+, TRACI 2, AUSLCI, RECIPE are reviewed. Different evaluating impact categories, criteria for their selecting and general methodological structure is discussed in the manuscript as well. [ABSTRACT FROM AUTHOR]