Frequently, correct evaluation of space-occupying lesions in the tongue is not possible with clinical methods only. In an attempt to assess the value of sonography in the detection of tongue lesions, we used submental sonography to examine 62 patients with suspicious palpatory findings upon physical examination of the tongue. Ultrasound detected 45 out of 47 tumours that were eventually confirmed either by surgery or by biopsy. Inadequate technique was the only factor that affected the detection rate. Sonography appears to be a reasonable guide in determining size and site of a tumour of the tongue. Thus, more precision in therapy planning may be achieved.