A group of 23 Air Force Lieutenant Colonels who attended a long General Staff Course were studied with assays of blood lipid fractions, 11-hydroxycorticoids and excretion of epinephrine, norepinephrine, free 11-hydroxycorticoids, 17-hydroxycorticoids (17-OHCS), dehydroepiandrosterone (DHA) and 17-ketosteroids (17-KS). More or less continuous emotional stress was expected as most of these subjects had familiar responsabilities and the course was extremely competitive, with a large percent of dropouts. This meant, for most of these officers, the end of their careers. Norepinephrine levels were significantly increased and correlated with aggressive behaviour. Significant (p < 0.001) elevations of plasma and urine-free 11-hydroxycorticoíds were registered showing levels in the range found in very stressed subjects. Blood total lipids and cholesterol raised significantly during the course, with levels comparable to those found in hyperlipidemic patients with coronary arteriopathy. The EKG changes were not significant. The possibility that this maintained stressful state might cause a hyperlipoproteinemia and consequent atheromatosis and coronariopathy is discussed.