Cytology and biopsy under direct vision using a fiberscope as microscopic diagnostic procedures for carcinoma of the esophagus and stomach were described, and results of cytology were evaluated as compared with the results of biopsy. The diagnostic accuracy of brushing cytology under direct vision using a fiberscope was 97% in 116 cases of esophageal carcinoma and 78% both in 119 patients with carcinoma of the gastric cardia and in 63 patients with gastric carcinoma exclusive of the cardia. The diagnostic accuracy for cytology of pancreatic juice collected by cannulation in 36 patients with carcinoma of the pancreas was 56%: 79% for carcinoma of the head of the pancreas, but only 35% for carcinoma of the body and/or tail. For the esophagus and stomach, the diagnostic accuracy of direct vision biopsy has become almost as high as with cytology. As such biopsies are easily performed, esophagogastric cytology has become a supplementary routine to the biopsy, and is done in a limited number of cases in which the biopsy failed or was not appropriate. Cytology of the pancreas, in which biopsy is difficult, is important as the only microscopic diagnostic procedure. The development of newer instruments and the improvement of techniques of cell collecting are required, as is the development of expertise in the interpretation of cells from pancreatic carcinoma, in which the diagnostic accuracy is still relatively low.