A Chilean publication in 1969 reported the 5-year survival rate of gastric cancer to be 12% of operated patients and only 3% of all patients diagnosed with gastric cancer. Encouraged by the excellent results obtained in Japan through a massive study of the population, Chile initiated in 1978 a program for massive detection of gastric cancer. From May 1978 to December 1986, 42,492 persons were screened under this system. Gastric cancer was detected in 0.43% in the massive group, and in 1.27% in the symptomatic group. The rate of early cancer detected per all gastric cancer was 14.69% in the former and 11.02% in the latter group. Gastric ulcer was found to be located more in the upper third of the stomach and less in the lower third, which may call attention in comparison with the foreign literature.