A clinical case of successful application of platelet-rich fibrin (PRF) to eliminate a large residual cavity after enucleation of a radicular cyst is described. The method is based on the use of biological substances that produce growth factors that stimulate reparative osteogenesis. A similar source of growth factors is PRF. According to the literature, it is able to reduce inflammation of periodontal tissues, preserve the location of the alveoli and eliminate defects in the alveolar bone, thereby enhancing bone regeneration and ensuring its good stability. PRF is easy to manufacture, does not require the appointment of anticoagulants, is resistant to stretching and elastic, while it can be used independently and in combination with various bone plastic materials. In our study, the use of PRF allowed not only to eliminate a large residual cavity after enucleation of a radicular cyst, which was confirmed by the results of cone beam computed tomography, but also to preserve the functionality of the teeth in an aesthetically significant area.