Base of tongue (BOT) is a difficult subsite to examine clinically and radiographically. Yet, anatomic delineation of the primary tumor site, its extension to adjacent sites or across midline, and endophytic vs. exophytic extent are important characteristics for staging and treatment planning. We hypothesized that ultrasound could be used to visualize and describe BOT tumors. Transcervical ultrasound was performed using a standardized protocol in cases and controls. Cases had suspected or confirmed BOT malignancy. Controls were healthy individuals without known malignancy. 100% of BOT tumors were visualized. On ultrasound BOT tumors were hypoechoic (90.9%) with irregular margins (95.5%). Ultrasound could be used to characterize adjacent site involvement, midline extent, and endophytic extent, and visualize the lingual artery. No tumors were suspected for controls. Ultrasonography can be used to transcervically visualize BOT tumors and provides clinically relevant characteristics that may not otherwise be appreciable.