This study was designed to (1) compare "predictive" abilities of different parameters and their interrelationships in the future incidence of coronary heart disease (CHD) and (2) define the profile of coronary-prone males through retrospective analysis of prospectively obtained data. Comprehensive studies of overt behavior pattern, blood lipids and coagulation, body measurements, socioeconomic factors, individual habits, and cardiovascular status were obtained annually since 1960 in 3,524 men, aged 39 to 59 years. Manifest CHD was found in 113 of 3,411 "well" men, but this was unknown to the investigators at the time of the study. The men with CHD exhibited higher serum beta/alpha lipoprotein ratios and 80 of them had been adjudged in "blind" assessments to exhibit an overt behavior pattern (type A) previously found associated with occurrence of CHD in middle-aged men.