Erectile function is markedly affected by acute alterations in circulatory homeostasis of which coronary artery bypass graft surgery is an excellent model. A group of consecutive patients who had undergone coronary artery bypass surgery 6-12 months previously were selected for detailed review by questionnaires that scored their pre-operative and post-operative sexual function and erectile ability and aspects of the quality of life. Thirty patients were evaluable. 10 men (33.3%) had poor erectile function before surgery. Eleven out of 30 men reported an improvement in erectile function while 10 men experienced a decrease or cessation of erectile function. Four of the five patients reporting new post-operative erectile function had had good pre-operative function suggesting that the surgery was directly associated with the impotence in these men. This pilot study suggests that coronary artery bypass surgery can have a significant impact in erectile function.