Platelet-rich plasma (PRP) has been proposed for different applications in the medical field and in maxillofacial surgery thanks to its many growth factors, such as epidermal growth factor (EGF), fibroblast growth factor (FGF), and keratinocyte growth factor (KGF). Oral lichen planus (OLP) is a disease that affects the oral mucosa in a chronic way. This disease frequently worsens the quality of life of patients, particularly when clinical manifestations are of the erythematous or erosive/ulcerative type. The properties of PRP that are supported by scientific literature in both oral medicine and other medical fields have suggested the introduction of PRP in clinical practice for the medical treatment of different soft tissues diseases, such as when OLP patients do not respond to conventional therapies, or when conventional treatments have some contraindications or side effects. The aim of this work is to describe the use of PRP used as an oral rinse for the treatment of a patient diagnosed as affected by OLP at the Dentistry, Special Needs and Maxillo-Facial Surgery Unit of the Hospital of Piacenza. PRP protocol was started after the failure of conventional therapies based on the use of topical and systemic corticosteroids, hydroxychloroquine, and low-level laser therapy applications.