High-frequency ultrasound can provide high-resolution imaging for diagnosing diseases of the head and neck. Over the last few years, a virtual technical evolution has led to the development of small and flexible ultrasound transducers with even greater anatomic resolution. The aim of the present study was to evaluate the efficacy of this new technique for imaging normal and altered anatomical structures of the endolarynx. Specially developed high-resolution, real-time ultrasound transducers (10 and 20 MHz) placed on the tip of endoluminal catheters were inserted into 20 autopsied larynges and five laryngectomy specimens. In a standardized examination process the endolarynx was analyzed in a real-time mode. Using this technique, exact 360 degrees cross sections of the larynx were obtained, demonstrating that it was possible to image the structures of the endolarynx with ultrasonography. Depending on the frequency used, all anatomical structures could be visualized up to a depth of 2 cm. In laryngeal cancer the depth of tumor as well as its relationship to the laryngeal framework could be clearly recognized. These findings suggest that this new endoluminal sonographic procedure represents a potentially important diagnostic tool in the assessment of laryngeal carcinoma.