Conventional radiographs of the paranasal sinuses were interpreted by two observers and were compared to A-mode ultrasound scans in 100 consecutive patients with classical symptoms of chronic sinusitis. Of the maxillary sinus radiographs 65% were reported as normal by one radiologist. There was poor agreeement between the observers in interpretation of the radiographs and both observers’ interpretations correlated poorly with ultrasound scans. Compared to radiographs, ultrasound had a sensitivity of 31% and specificity of 63% in detecting abnormalities. We suggest that positive imaging tests in chronic sinusitis may not truly reflect the incidence of a pathologic condition and that comparison of images with other parameters (e.g., response to treatment) is needed to ascertain the role of the images in chronic sinusitis.