The incidence of atherosclerotic coronary artery diseases (CAD) was assessed in 4,576 male participants of the Prospective Cardiovascular Munster (PROCAM) study, aged 40-64 years, over a 4-year follow-up period. In this time, 122 study participants developed atherosclerotic CAD (89 definite nonfatal myocardial infarctions and 33 definite atherosclerotic CAD deaths). Univariate analysis revealed a significant association between the incidence of atherosclerotic CAD, and high-density lipoprotein (HDL) cholesterol (p <0.001) and triglyceride (p <0.0) levels. The relation to HDL cholesterol remained after adjustment for other risk factors. By contrast, the relation between the incidence of atherosclerotic CAD and triglycerides disappeared if, in a multivariate analysis by means of a multiple logistic function, cholesterol or HDL cholesterol was taken into account. However, the data suggested that hypertriglyceridemia is a powerful additional coronary risk factor, when excessive triglycerides coincide with a high ratio (<5.0) of plasma low-density lipoprotein (LDL) cholesterol to HDL cholesterol. Even though the prevalence of this subgroup was only 3.7%, it included a quarter of all atherosclerotic CAD events observed.