The result of reirradiation in recurrent T1 (rT1) nasopharyngeal carcinoma (NPC) is unsatisfactory. We sought to study the efficacy and complications of endoscopic microwave coagulation therapy (MCT) in salvaging rT1 NPC after primary radiotherapy. Between August 1994 and April 2005, 55 patients with rT1 NPC were treated with endoscopic MCT. With a median follow-up of 102.1 months, 52 of 55 patients are still alive. Five patients had local failure after retreatment. The overall survival and local progression-free survival were 100% (95% CI, 99.4% to 100%) and 94.5% (95% CI, 94.1% to 94.9%) at 2 years, respectively, and 93.6% (95% CI, 93.5% to 94.4%) and 90.7% (95% CI, 90.2% to 91.2%) at 5 years. The common complications of endoscopic MCT were mild postoperative pain and headache. Nasopharyngeal necrosis was transient in one patient and subsided in 1 month. Endoscopic MCT achieved significant survival and tumour control without severe complications in selective rT1 NPC.