To evaluate re-irradiation using IMRT for recurrent and second primary head and neck cancer in previously irradiated territory.Between 1997 and 2008, 84 patients with recurrent and second primary head and neck cancer were treated with IMRT to a median dose of 69Gy. Median time interval between initial radiotherapy and re-irradiation was 49.5 (5.2–298.3) months. Salvage surgery preceded re-irradiation in 19 patients; 17 patients received concurrent chemotherapy.Median follow-up of living patients was 19.8 (1.9–76.1) months. Five-year locoregional control and overall survival were 40% and 20%, respectively. Five-year disease-specific survival and disease-free survival were 29% and 15%, respectively. Stage T4 (p=0.015), time interval between initial treatment and re-irradiation (p=0.011) and hypopharyngeal cancer (p=0.013) were independent prognostic factors for worse overall survival in multivariate analysis. Twenty-six and 11 patients developed Grade ⩾3 acute and late toxicity, respectively. No Grade 5 acute toxicity was encountered. There were 2 fatal vascular ruptures during follow-up.High-dose IMRT for recurrent and second primary head and neck cancer in previously irradiated territory leads to ≈20% long-term survival in a non-selected patient population. Identification of patients who would benefit most of curative IMRT is warranted.