Objective: This quasi-experimental study compared the effectiveness of chewing gum and gargling with a saline solution as two types of intervention to reduce oral mucositis scores. Method: The sample consisted of 44 children who were divided into two groups, one of which chewed gum, and the other gargled with a saline solution. The Mann-Whitney U test was used to analyze the data. Results: There was a significant difference (p = 0.001) in post-intervention oral-mucositis scores. The significant mean difference between the groups indicated that the decreased oral mucositis scores for the chewing gum group was more substantial than for the group gargling with a saline solution (p = 0.001). Conclusions: The data showed that chewing gum is more effective than gargling with a saline solution, and it can be incorporated into the nursing protocol for treating pediatric cancer patients.