Traditional and nontraditional risk factors for coronary heart disease (CHD) are discussed with special attention devoted to the Type A behavior pattern (TABP). Positive and negative epidemiological evidence bearing on the risk factors status of global TABP is reviewed. Results of the review suggest that component scoring of the multidimensional global TABP in attempts to uncover "toxic" components, particularly Potential for Hostility, is a profitable research strategy. Similarly, evidence is presented that suggests merit in component scoring of hostility, also a multidimensional construct. To explicate more fully the nature of Potential for Hostility and its categories, correlations between the SI-derived ratings and ratings of established dimensions of individual differences based on the five-factor taxonomic model of personality from subsamples of the MRFIT and WCGS studies are presented. Total Potential for Hostility and especially the Style of interaction category show highly significant relations to Low Agreeableness or Antagonism. High ratings of Potential for Hostility identify individuals who can be described as uncooperative, antagonistic, rude, disagreeable, unsympathetic, callous, and the like. Implications of the evolving concept of coronary-prone behavior, as distinguished from TABP, are briefly considered.