We studied the effects after cigarette quicksmoking in 15 subjects on plasma catecholamines levels (epinephrine and norepinephrine), on heart rate and arterial pressure. Smoking-associated increments in mean plasma norepinephrine and epinephrine as well as in heart rate and arterial pressure were demonstrated. The lack of correlation between the increase of the adrenergic system activity and this of the hemodynamic parameters can be explained by their own different characteristics.