The purpose of the research is to evaluate terms and improve definitions related to conformity assessment for development of a unified totality of terminology in this field in Latvian language. In order to make analysis, different qualitative research methods, including assessment, analysis and comparison were used by applying inductive and deductive methodologies. As the main sources for research were used books, publications, national and international laws and regulations, standards and other binding documents applicable to the field of conformity assessment. The terms and definitions related to conformity assessment and its components (accreditation, certification and metrology) are evaluated with a purpose to improve the current definitions or to suggest the new ones, thus developing unified and coordinated totality of the terms which corresponds to contemporary understanding of conformity assessment. One reason of the conformity assessment related problems is insufficient number of scientific publications in Latvian. On the basis of assessment of the terms the authors proposed updated translation of the terms ‘notified body’ and ‘harmonized standard’, as well as, substantiated application of the term ‘measuring instrument’ in Latvian. As a result of the research the authors worked out proposals for improvement of definitions in Latvian for the terms ‘conformity’, ‘assessment’, ‘conformity assessment’ and ‘standardization’ and developed new definitions for the terms ‘conformity assessment procedure’, ‘notified body’ and ‘harmonized standard’. In order to facilitate proper understanding by all involved parties about conformity assessment procedures an explanation of the essence for each procedure is developed. The results of the research will facilitate better comprehension about placement of goods into the market, thus diminishing a possibility to place into the market and to use unsafe goods.