In Japan the type A behavior pattern, particularly its component of hostility, is known to have less value as a risk for coronary artery disease (CAD) than in the United States. We developed a questionnaire (Japanese Coronary-prone Behavior Scale [JCBS]) to investigate the behavioral correlates with CAD among contemporary Japanese persons. The JCBS was administered to 419 Japanese men undergoing coronary angiography; 310 of them had angiographic or clinical evidence or both of CAD, and 109 had no evidence of CAD. The group with CAD had more coronary risk factors than the group without CAD, but the two groups did not differ in type A behavior pattern as assessed with the Jenkins Activity Survey. Stepwise discriminant analysis, in which standard coronary risk factors were forced into the model, revealed that inclusion of nine JCBS items (scale C) in the model resulted in the best discrimination between the two groups. Cross-validation results showed that the error-rate estimates for the discriminant models that consisted only of standard coronary risk factors, only of scale C items, and of their combination were 34.7, 32.4, and 27.0%, respectively. The scale C items represented a job-centered lifestyle, social dominance, and suppressed overt type A behaviors. These results indicate that an independent behavior pattern prone to CAD is discernible among Japanese men and suggest that the behavior pattern may contain characteristics that can be differentiated from those that constitute the type A behavior pattern. (Am Heart J 1997;134:1029-36.)