Due to anatomic distortion or surgical complications, it may be difficult to determine the precise position of an implanted Molteno tube. We performed ultrasound biomicroscopy (high-resolution ultrasound) to test the usefulness of this modality in localizing implanted Molteno tubes in 10 patients with Molteno tubes. A 50-megahertz transducer with a penetration of approximately 4 mm was used to produce a magnified image of the anterior segment. The Molteno tube was visualized without complication in all of these cases.