With the aid of an image quantifier, the distribution of histochemically labelled (alcian blue, pH 2.5) mucin-producing goblet cells was recorded from a gastrectomy specimen with a peptic ulcer to determine the degree of metaplasia. Of 254 measurements made, 130 were in the antrum and 124 in the fundic area. The areas occupied by cells positive for alcian blue were 7.5 (SD 9.89)% in the antral region, and 1.8 (1.84)% and 0.92 (1.15)% in the two zones representing the fundic area. The difference between the positive mucosal areas in the antrum was significantly higher (p less than 0.001) than in the fundic area. The positively stained area found along the lesser curvature was 7.76 (12.0)% while along the greater curvature, it was 2.17 (3.02)% (p less than 0.001). This method will be useful for future studies of the extent and topographical distribution of intestinal metaplasia among populations with disparate incidences of gastric carcinoma because it permits comparison of different areas of intestinal metaplasia in mucous gastric zones.