High-resolution real-time sonography of the biceps tendon was performed on 80 patients referred for shoulder arthrography. The arthrograms and sonograms were compared at the levels of the biceps tendon groove and distal tendon. Sonography and arthrography were equally successful in facilitating the evaluation of the bony configuration of the biceps tendon groove, but sonography gave a superior image of the biceps tendon within the groove. In 16 patients, biceps tendon sheath effusions or swelling was detected using sonography; 15 of these patients had associated pathologic conditions elsewhere in the joint. Arthrograms did not disclose a biceps tendon or sheath abnormality in any of these patients. We conclude that sonography could be the imaging method of choice in patients with suspected biceps tendon lesions and that the presence of a biceps tendon or sheath abnormality indicates an increased likelihood of abnormalities elsewhere in the joint.