The results are presented of afterloading high-dose-rate-radiation with iridium-192 in 34 patients with squamous cell carcinomas of the floor of the mouth and tongue. Some patients were also treated surgically or given percutaneous radio- or chemotherapy. At the time of diagnosis, 28.0% had a T2 tumour, 41.9% a T3 tumour and 30.1% a T4 tumour, 41.2% had positive lymph nodes and 2.9% distant metastases. The response rate was 64.7%, 26.5% of which were complete remissions and 38.2% partial remissions. In 61.8% of cases, the tumour was recurrent and responded with a rate as high as 57.2%, 23.9% of which were complete remissions and 33.3% partial remissions. Survival times were dependent upon therapy results. The mean survival of patients with complete remission was 40.3 months, with partial remission 16.1 months as opposed to 7.2 and 3.5 months respectively in patients showing no change or progressive disease. It can be concluded that afterloading therapy using high-dose-rate-radiation with iridium-192 achieves good palliative results and should be looked at as a supplementary treatment modality for squamous cell carcinomas of the floor of the mouth and tongue.