The patient-centered approach in modern healthcare involves the active use of patient-reported outcomes (PRO) and patient-reported outcome measures (PROM). PROs and PROMs are applied in both clinical trials and real-world evidence studies, providing unique information about patients’ health status that cannot be obtained through other methods. There are numerous regulatory documents and specialized databases with validated questionnaires for PRO assessment. An important aspect is the proper selection of tools for specific research or tasks, taking into account the population, research objectives, and measurement properties of PROMs. This article systematizes all current documents regulating work with PROs and describes in detail the algorithms for validating translated questionnaires. A special attention is paid to the process of linguistic and cultural adaptation of questionnaires, including forward and backward translation, assessment of psychometric properties, and validation in target population. The article also examines practical aspects of PROMs in research, specifics of registering PROs on clinicaltrials.gov, and challenges of applying PROs In Russia, including the lack of Russian validated versions of several questionnaires and difficulties with license payments. The article provides comprehensive guidance on working with PROs for researchers and practitioners, emphasizing the importance of including PROs in research protocols and the need to follow recommendations for their use at all study stages.