ABSTRACT The purpose of this study was to achieve locoregional control of locally advanced laryngeal carcinoma, survival, and organ preservation using split hyperfractionated accelerated radiation therapy and cisplatin concomitantly. This study was a phase II trial of chemoradiotherapy with split hyperfractionated accelerated radiation therapy, 1.6 Gy per fraction given twice per day to a total dose of 64 to 67.2 Gy for a total of 6 weeks with a 2-week gap, and cisplatin 20 mg/m2, days 1 to 5, in continuous perfusion, concomitantly. Seventy-three patients were treated (stage IV, 64%). At a median follow-up of 55 months for living patients, median survival was 44 months, and 5-year overall survival and disease-free survival were 42% and 39%, respectively. Toxicities included mucositis (grade III, 40%; grade IV, 28%), epithelitis (grade III, 28%). Of the 73 patients, 32 (44%) have continued with their larynx free of disease. Split hyperfractionated accelerated radiation therapy and concomitant cisplatin has been demonstrated to be an active treatment for locally advanced laryngeal carcinomas, but more active combinations of chemotherapy and radiotherapy, without increase of toxicity, are necessary to increase the rate of locoregional control, organ preservation, and survival.