Chemoradiotherapy for head and neck cancer is associated with a high incidence of severe oral mucositis; an adverse, painful event. Oral mucositis also causes nutritional deficiency by making oral feeding difficult. This may lead to prolongation of hospitalization due to complications caused by malnutrition. However, an effective way to prevent oral mucositis completely, remains to be found. In this study, we evaluated the occurrence of oral mucositis, and nutritional conditions such as hypoalbuminemia, reduction of body weight, and length of hospital stay (days) when the mouth was rinsed using rebamipide solution (R solution), or Poraprezinc-alginate sodium solution (P-A solution) (both considered to be effective for oral mucositis). A mouth rinsed with sodium azulene sulfonate (S solution) was used as a control. The mouth was rinsed out six times per day continuously during chemoradiotherapy. In the study, 31 patients were assigned to rinse their mouths using R solution, 11 patients using PA solution, and 15 patients using S solution (reduction rate of body weight in 14 patients). For the evaluation, the criteria for adverse drug reactions CTCAE (v3. 0) were used. Grade 1 and over, oral mucositis occurred in 48% of the R solution group, 36% of the P-A solution group, and 80% of the S solution group, indicating that the P-A solution group significantly prevented the occurrence of oral mucositis as opposed to the S solution group. A reduction in body weight was observed in 81% of the R solution group, 82% of the P-A solution group, and 79% of the S solution group, indicating a similar weight reduction rate among individual solution groups. Hypoalbuminemia equal to grade 2 or higher occurred in 3% of the R solution group, 18% of the P-A solution group, and 29% of the S solution group, indicating that the R group significantly prevented the occurrence of hypoalbuminemia compared to the S solution group. In addition, the length of hospital stays were 44 ± 8. 0 days for the R solution group, 52 ± 18. 8 days for the P-A solution group, and 61 ± 19. 5 days for the S solution group, indicating that the R solution group significantly shortened the length of hospital stay compared to the S solution group. These results suggested that the use of an R or P-A solution may be effective in preventing oral mucositis and impaired nutrition of those undergoing chemoradiotherapy for head and neck cancer.