We have examined normal and inflamed oesophageal biopsies for the distribution of alpha-D-mannosyl and alpha-D-glucosyl residues using the concanavalin A--horse radish peroxidase--Diamino-benzidine (DAB) technique at the light and electron microscope level. Receptors were found on the epithelial surface and in the nuclear membrane and endoplasmic reticulum. A similar distribution was found with the intrusive lymphocytes and polymorphonuclear leucocytes in the inflamed state. Some of the increased intercellular debris from inflamed biopsies contained concanavalin A receptors.