Aim To evaluate the frequency of off-label prescription of medicines in practice of clinical specialists and the awareness of respondents of the procedure of justified off-label prescription.Material and methods The sample included 542 clinical specialists who worked in definite medical organizations in 26 entities of the Russian Federation. The respondents were proposed to fill in remotely an anonymous questionnaire to evaluate the experience of prescribing medicines off-label to adult patients.Results Prescribing medicines not in consistence with the officially approved instruction for medical use (off-label or "outside instruction") is a relevant issue of global medical care since convincing scientific evidence for safety of such use is scarce. Analysis of information about off-label prescription is one of current tasks of national medical research centers according to the Federal Project "Development of a network of national medical research centers and implementation of innovative medical technologies". According to the responses about the frequency of off-label prescriptions 67.5 % of respondents reported of no experience of off-label prescription, 27.7 % said "rarely" or "sometimes", and 4.8 % said "frequently" and "very frequently". Specialties of physicians who have more often used medicines off-label (50% and more) included obstetrics and gynecology, pediatrics, rheumatology, hematology, and pulmonology. Cardiologists, neurologists and clinical pharmacologists use medicines off-label relatively rarely (19.6%, 28.6 %, and 22.2 %, respectively). 40 % of medicines used off-label were those designed for the treatment of coronavirus infection SARS-CoV-2. The medicines most frequently used off-label included metformin, rituximab, and thioctic acid. 65 % of respondents assessed their knowledge of off-label prescription as insufficient. In addition, 75 % of respondents consider it useful to receive additional information about risks and benefits of off-label prescription in clinical practice.Conclusion The survey revealed the need of physicians for information about risks of the off-label use of medicines in clinical practice.