An analysis was done for the diagnostic accuracy of radiological and endoscopic examinations in 132 cases of the histologically proved stomach cancer at the National Medical Center from Jan. 1975 to Jan. 1979. the problems in radiological misdiagnosis was especially discussed aimed to improve the further diagnostic accuracy. The following results were obtained: 1. The incidence of the stomach cancer was higher in male than that of female, and was most prevalent in 5th and 6th decades. 2. The misdiagnosis rate of radiological examination of the stomach cancer was 13.5% (18 cases), that of endoscopic examination was 8.3% (11 cases) and that of both examinations was 4.6% (6 cases). 3. In most cases of misdiagnosis, the majority were diagnosed as benign gastric ulcer. 4. The causative factors of misdiagnosis in radiological examination were interpretation error in 8 cases and technically poor, unsatisfactory study in 10 cases. 5. In order to decrease the misdiagnosis rate, standar ization of radiological examination and careful interpretation are necessary. 6. Complemental examinations of radiology and endoscopy can decrease the misdiagnosis rate.