The number of people examined in "the Japanese Stomach Cancer Examination" programs under "Health Services Law for the Aged" has not increased, and a strategy is needed to increase participation in the programs. We have thought out a plan to persuade people to the programs by using serum pepsinogen tests without changing the framework of the programs. The plan is as follows: The subjects are those who undergo phlebotomy in "the General Health Examination" programs and who do not undergo the Stomach Examination programs. Serum pepsinogen levels are measured using the sera and those with high risk for stomach cancer are persuaded to attend "the Stomach Examination" programs. To estimate the effect of the plan, we asked several local governments to complete a questionnaire on the numbers of subjects. The ratio of the number of the subjects in the plan to the number of screenees in recent Stomach Examination programs was 0.61. An increase of about 15% was expected in screenees of the Stomach Examination Programs, if 40% of the subjects in the plan were diagnosed as high risk and 60% of the high risk subjects attended the Stomach Examination programs. From the economical stand point, it was expected that detection rate would increase and that the plan did not raise the cost for detecting a patient with stomach cancer. We also conducted a questionnaire survey of those who would be the subjects of the plan. Eighty-two percent of the subjects answered that they would attend the Stomach Examination programs, if they were told that their risk of stomach cancer was high by the serum pepsinogen tests. These results seem to suggest that more people would participate in cancer examination programs when informed that their risk for cancer is high as determined by blood tests.