Subject. The article discusses the assumptions and methods for measuring the fair value of assets for various purposes in the Russian practice. Objectives. The study analyzes and examines the application, concept and methods for the fair value measurement. We also suggest how entities should avoid errors in financial and administrative decision-making processes, when referring to the fair value. Methods. In this study, we rely upon the methods of synthesis, deduction, induction, and analysis of relevant special literature and regulatory documents. Results. The Russian practices of fair value were found to have several practical applications, which differ by purpose, substance and generation techniques, which cause identical assets to be different in value, and incorrect financial decisions. The assumption on the open market sale or sale between a certain seller and buyer, and the application/non-application of the best use principle were discovered to serve as key criteria and reasons generating the fair value, which causes its measurements to differ. The article provides the rationale for ensuring the consistency of the substance and methodology for the fair value generation for various purposes in the Russian regulatory documents or using the alternative terminology to denote the value generated differently from the fair value at the initial source. Conclusions. The conclusions can serve for further formulating theoretical principles for fair value measurements in financial accounting of profit-making entities and public institutions. They also can be used to measure the fair value of pledges, converge or develop new regulatory documents in Russia in terms of the substance and methodology for measuring the fair value, preventing errors in financial and administrative decision-making based on the fair value of assets, which is measured for various purposes.