We have treated 7,014 cases with the CyberKnife (CK) system over 13 years. Of them, 1,317 cases were head and neck cancer patients. Lately, reirradiation by using the shrinking field technique for recurrent cancer is topical. 80% of our patients were reirradiation cases. The median overall survival rate was 13.5 months. Reirradiation is feasible, but 20% of these patients showed CTCAE Gr III adverse events. Careful selection of indications is essential.