Catecholamine excretion, cholesterol, triglycerides, free fatty acids (FFA) and plasma 11-OH corticoids were measured in 18 normal workers of an aircraft factory exposed to turbine noise for 3 h. Blood pressure and pulse frequency were also registered. In 72% of the subjects, marked elevations of catecholamine excretion were found, correlating fairly well with increases of cholesterol, FFA, blood pressure and pulse frequency. Surprisingly, after 3 h of noise exposure, the plasma 11-OH corticoid mean value was slightly lower than the one of the early morning in resting conditions; this could be ascribed to the pronounced midday drop of plasma corticoids, characteristic of the circadian cortisol variation. This could counteract the moderate corticoadrenal stimulation caused by the noise stress. The blood pressure and plasma lipid elevation found in these workers might be detrimental to personnel suffering from atherosclerosis or other vascular pathology.