Of 376 patients who were treated by radical radiotherapy for squamous carcinoma of the larynx, 56 subsequently underwent total laryngectomy. Residual or recurrent tumour was identified in 43 of the resection specimens, and necrosis alone in 13 cases, although a positive biopsy had been obtained in 3 of these prior to salvage laryngectomy. No disease related factors such as site or stage of the original tumour, or treatment related factors such as radiation type or dose, were found to be predictive of whether or not tumour was present. The clinical opinion of an experienced surgeon was found to have a positive predictive value of 0.86 for the presence of tumour. The fistula rate of salvage laryngectomy, 15 out of 56, was similar to that of other series. The actuarial cause specific 5-year survival for patients with tumour was 0.589, and for patients with necrosis only was 0.923. Intercurrent, smoking related disease was the cause of death in 16 of the 33 patients who have died.