Sonography has proved superior to CT and MRI for imaging T1 or T2 carcinomas of the oral cavity and base of the tongue. However, in examining the anterior half of the tongue and the floor of the mouth problems arise due to absorption of sound by the mandible and air inclusion. Ultrasound examination can be performed end-orally by means of a miniaturised transducer. End-oral sonography produces images of the anterior parts of the tongue and the floor of the mouth without artefacts. This method is superior to conventional transcutaneous sonography for this region.