At the present time no satisfactory figures are available concerning the incidence of heart disease noted in mass roentgenographic surveys of the chest conducted throughout the nation. In order that information on this subject might be secured a pilot project was started in 1949. Maclean and Rogen of Glasgow reported data on such a survey, but their patients were in the younger age groups.1 The report by West2 did not include actual measurements of heart size. Edward's report3 dealt with a predominantly Negro population, and no definite heart measurements were recorded. Many other reports were noted in the literature, but no accurate data in regard to heart disease were recorded. METHODS AND MATERIAL The present report was made possible when the Cincinnati Antituberculosis League and the Cincinnati Health Department made examinations of the chest x-rays of 10,549 persons in the early part of 1949. There were 486