Objective To explore an effective method for preventing and treating oral mucosal complications of radiotherapy for head and neck cancer. Methods Fifty head and neck cancer patients who were receiving radiotherapy were enrolled between March, 2008 and March, 2010. These patients were randomly assigned to the treatment group and the control group. During the radiotherapy, patients in the treatment group were given IL-11 in the form of atomization inhalation,whereas patients in the control group were not. Results IL-1 1 was well tolerated by the patients. It significantly decreased the level of oral mucosal complications and pains and improved patients' appetites ( P < 0.05 ). In addition, the duration of pain was significantly ( P <0.05 ) reduced from 4.5 ± 1.3 days ( in control group) to 2.3 ± 1.0 ( in treatment group), and the healing period was also significantly ( P < 0.05) reduced from 7.3 ± 1.5 days ( in control group) to 4.1 ± 1.7 ( in treatment group). Conclusion IL-11 is effective in preventing and treating oral mucosal complications of radiotherapy for head and neck cancer,relieving associated pains, and therefore improving patients' quality of life.