Oral complications are a common side effect of cancer chemotherapy, as antineoplastic agents affect both the immune system and the oral mucosa. This study demonstrates preventive and therapeutic effects of dental treatment and regular use of Weleda Ratanhia-Mundwasser((R)) (herbal mouthwash) and Weleda Pflanzen-Zahngel((R)) (herbal toothgel) on oral mucositis during chemotherapy. Thirty-two female patients with breast cancer starting on chemotherapy were evaluated in this study. Plaque index, gingival index, degree of mucositis and 10 single symptoms were monitored once weekly for four consecutive weeks. After four weeks, plaque and gingival indexes were slightly decreased compared to baseline values. The degree of mucositis was increased by one grade in 15.6 % of the patients and over 70 % remained without symptoms. On the whole, single symptoms decreased from day 7 since beginning of chemotherapy to day 28. Mucositis symptoms were moderate in severity, and the results indicate a positive influence of using Weleda Ratanhia-Mundwasser and Weleda Pflanzen-Zahngel. Further studies might be promising.