The paper focuses on the use of online lexicons in the translation process. A number of online lexicons containing agricultural and environmental terminology are considered. It analyses the ways in which translators use online lexicons and finds that they can be a source of terminological and supplementary information. Comparisons have been made between the printed and online versions of the lexicons and a number of advantages of the online lexicons have been identified. The continual updating of the entries in the online lexicons and the increasing amount of data contained in them were found out. The usefulness of hyperlinks, which allow the use of not only one particular lexicon but also other related Internet sources, is highlighted.