ENTexts of legal (official) style are characterized by officialese and standard linguistic expression, but a certain variety is allowed. As a result there’s good reason to discuss the synonymy in texts of the style mentioned above. The usage of derivational synonyms, i.e. words derived from one root with various derivational means, is especially interesting and already investigated to a small degree. Several groups of derivational synonyms (e.g. words derived with suffixes and inflectional derivatives; various suffixational derivatives; various prefixational derivatives) may be singled out in legal acts, resolutions and other documents of the Latvian language. The variety of functioning of these groups is discussed in the present article. The most often met pairs of synonyms (even recorded in terminological dictionaries) are the following: terms derived with suffixes and appropriate inflectional derivatives, also, terms derived with a help of two – usually Latvian and international – suffixes. Some of them are included in terminological dictionaries, e.g. inventarizēšana, inventarizācija. Sometimes the terminological dictionaries reflect the nuances of meanings of the terms which are created by derivational means, and it is possible to discuss the distinctive terms; practical usage does not always accord with the requirements of the standardized terminology.