The HID-AB histologic staining technique, which distinguishes sulphomucin from sialomucin types of intestinal metaplasia, was employed in endoscopic gastric mucosal biopsies to evaluate their frequency of association with epithelial dysplasia. Sulphomucin-type intestinal metaplasia was found in 33% of the cases under observation; moderate or severe dysplasia was only associated with this type of intestinal metaplasia. Its precancerous significance can be ascertained only by means of prospective studies.