Objectives This study investigated the ability of sonography for diagnosis of hypopharyngeal carcinoma. Methods Between November 2008 and January 2010, 34 consecutive patients with hypopharyngeal carcinoma (34 tumors) were examined by sonography. The visualization capability of sonography was evaluated by grading criteria of "excellent," "good," "moderate," and "poor" in comparison with computed tomography (CT). Localization of the primary tumor foci and intrahypopharyngeal and extrahypopharyngeal invasion were initially assessed by sonography and confirmed with surgical and pathologic findings. Laryngeal movement was observed on real-time sonography and compared with endoscopic findings. Results On sonography, 29 of the 34 lesions (85.3%) were graded excellent, similar to the shapes and dimensions of the tumors on CT. Localization was correctly undertaken in 26 of the 28 foci resected (92.9%), with excellent agreement between sonography and surgical and pathologic findings (kappa = 0.823; P < .001). In evaluating intrahypopharyngeal and extrahypopharyngeal invasion with sonography, the sensitivity and specificity were 90.9% and 82.4%, respectively, for intrahypopharyngeal intersubsite spreading, 50.0% and 96.2% for diagnosis of thyroid cartilage destruction, both 100% for evaluation of cervical esophagus, neck soft tissue, and thyroid gland involvement, and 76.9% and 100% for assessment of hemilarynx fixation. Conclusions Sonography has a similar role in visualization of hypopharyngeal carcinoma as CT and is satisfactory in localization of the primary focus and assessment of tumor extension inside and outside the hypopharynx.