The relevance of the quality of institutions evaluation increased after the recognition a slogan – "important institutions" by a scientific community. The article is based on the review of scientific publications carried out a classification of existing approaches to the assessment of institutions. Exclusive conceptual approaches (social, entropy, dysfunctional, costly, effective, pragmatic) and approaches implemented at the empirical level (comparative, legal, regulatory, and behavioral) were dedicated. A new key drawback of the popular method for institutional assessment – method ratings – was found. Modern methodological problems of assessing the quality of institutions regardless of the level of study were defined in this article. According to these problems the most popular are abstraction from the internal structure of the institutional system and the complementarity of its elements and concentration of estimates at the output of the system. For correcting actions of this key disadvantage the concept of the institutional option described on the example of small enterprises of the Russian industry was proposed. In conclusion part, practical importance of the concept in the assessment of the quality of institutions at all levels of study was presented.