Using a thin B-scan probe the anterior chamber angle was ultrasonographically studied using a contact eye cup filled with saline. The width of the chamber angle was measured on the display video copy and compared with the gonioscopic findings. Sixty-four eyes with primary glaucoma and 53 nonglaucomatous eyes were examined. In eyes with gonioscopic narrow angle the real ultrasonographic width of the chamber angle was varied considerably from case to case. In eyes where the chamber angle was not visible by gonioscopy it was not always closed. The correlation between the width of the angle and the depth of the anterior chamber was weak. There was often a plateau iris, which was demonstrated clearly by B-scan ultrasonography.