Background: Mucositis is a complex inflammatory response of the digestive system mucous membrane and it is also one of the most common painful side effects following chemotherapy in children with carcinoma. Developing to mucositis affects the patient's life severely and can lead to long – term hospitalization.Therefore, this study was conducted to evaluate the effect of chamomile mouthwash on the prevention of oral mucositis in children with acute lymphoblastic leukemia.

Materials and Methods: This double-blinded clinical trial study was done on 31 children with acute lymphoblastic aged 6-15 who were admitted to hospital of 17 Shahrivar Rasht, Iran between 16 July and 8December 2015. Patients and their parents were instructed to resolve 15 drops of chamomile mouth wash in 10cc water, turn it one minute in the mouth, outpour it, and avoid eating for one hour. After three times tooth brushing a day, the mouth cavity of patients was evaluated one day before chemotherapy, the seventh day and fourteenth day of chemotherapy according to the criteria of world health organization. SPSS (version 11)was used in order to analyze the data and random statistical index and independent t test were run.

Results: The severity of oral mucositis on the seventh and fourteenth day after chemotherapy had no significant difference with the first day (P = 0.59). The incidence and severity of oral mucositis didn't increase 14 days after chemotherapy in comparison with the seventh day.

Conclusion:  Chamomile mouthwash can be effective in preventing the incidence and severity of oral mucositis and it can be used as a suitable mouthwash in children undergoing chemotherapy.