From 1.1. 1986 to 31.12. 1990 50 patients with epidermoid carcinoma of the floor of the mouth and the mobile tongue (stage T1 18, stage T2 20, stage T3 eight and stage T4 four patients) were treated by surgery, 192-iridium implantation using the plastic tube technique and percutaneous irradiation. Surgery was performed as enoral resection (35 patients) or en bloc tumour resection with part of the mandible and flap reconstruction (15 patients). Interstitial therapy was considered as a boost to primary tumour region, the dose given ranged between 16 and 33 Gy. 50 to 60 Gy were applied with external beam radiotherapy. Management of the neck consisted of elective or radical neck dissection followed by external beam radiotherapy (50 to 60 Gy). At 2/1991 median follow-up was 17 (three to 53) months. 35 patients are alive and tumour-free, one patient lives with tumour. 14 patients died, eight patients tumour-related, four patients of intercurrent disease and two patients because of a second primary. Primary local control was 18/18 patients for stage T1, 19/20 patients for stage T2, 7/8 patients T3, 3/4 patients for stage T4. Three patients suffered from nodal recurrences, four patients from distant metastases. Complication rate was acceptable. Soft tissue necrosis occurred in 4/18 patients (T1); 5/20 patients (T2); 3/8 patients (T3) and 1/4 patients (T4). Three patients developed osteoradionecrosis. Our results show that combined modality treatment for tumours of the oral cavity yields high local control with acceptable complication rate.