Background: Mucosal injury is the consequence of biologic events coupled with the influence of the oral environment and microbiome. Oral mucositis is one of the most common toxicities of chemoradiation therapies. Incidence and severity varies by chemoradiation regimens, radiation fıelds, and tumor site. The influence of mucositis on quality of life is greater among patients than the medical literature would suggest. Lack of experience in evaluating treatment toxicities is a daily problem in cancer patients. The aim of this study was to assess the efficacy of verbascoside’s (mucosyte) oral solution on mucositis in cancer patients. Methods: Fourty-five patients with different grade mucositis treated with mucosyte (ranging from 1-2 to 6-7 rinses/day, according to the guidelines) were evaluated from October 2017 to June 2018. Patients were monitored every week until complete remission. Results: Of 45 patients enrolled, 5 had G1 oral mucositis at baseline, 21 had G2, 13 had G3 and 3 had G4. Three patients had G0 oral mucositis at baseline. Median age was 66.8 years. Six patients were treated with carboplatin/paclitaxel, and six with cisplatin/pemetrexed for non-small cell lung cancer; nine patients were treated with paclitaxel, six with adriamycin/cyclophosphamide, and two with eribulin for breast cancer; four patients were treated with FOLFOX for intestinal adenocarcinoma; three patients were treated with nab-paclitaxel/gemcitabine for pancreatic cancer; five patients were treated with cisplatin/cetuximab, and four with cisplatin/cetuximab plus radiotherapy for squamous-cell head and neck cancer. All patients reached complete remission in a median time of 14.9 days (10-24 days). Conclusions: Mucosyte treatment was able to rapidly shorten G3/4 oral mucositis to G1/2, and to never happen mucositis in G0 at baseline. Thus, we suggest that mucosyte can be effective both in prevention and treatment of mucositis.