This study compares prospectively the cardiovascular and catecholamine responses to central venous and pulmonary artery catheterization before and after induction of general anaesthesia. Twenty patients for elective coronary artery surgery were randomized into two groups. One group had central venous and pulmonary artery catheterization performed awake using local anaesthesia. The other group had these catheters inserted following induction of general anesthaesia. In all patients heart rate, arterial blood pressure, ST segment analysis and epinephrine and norepinephrine levels were measured prior to central venous cannulation and at 2-min intervals until placement of the lines was achieved. There were no statistically significant changes in any cardiovascular or catecholamine variable with time compared with the base–line measurements. There were no statistically significant differences in plasma catecholamine levels between the awake and the anaesthetized groups.