The present study aims to evaluate the effectiveness of a combined protocol of professional and at-home ozone therapy in the treatment of oral mucositis in patients undergoing radio- and/or chemotherapy. In-office treatment was performed using a medical ozone generator, while at-home therapy involved the daily application of high-concentration ozonated oil products. The study assessed the reduction in mucositis severity (WHO scale), decrease in pain (VAS scale), and improvement in patient-reported quality of life, with specific attention to nutrition, oral hygiene, and treatment adherence.