Immunohistochemical detection of carcinoembryonic antigen (CEA) was reported in mucocele and associated minor salivary glands of oral mucosa. Higher levels of staining for CEA occurred in salivary glands with attached mucoceles, in which acinar cells and ductal segments in the gland displayed concentrations of CEA higher than those in normal minor salivary glands. Floating cells also gave positive CEA staining, whereas epithelial fragments and connective tissue in the mucocele wall were lacking in CEA. It was suggested that mucoceles in oral mucosa accumulated CEA in associated minor salivary glands.