The authors report the case of an asymptomatic 67 year old patient, in whom, 6 years after aortic valve replacement, Doppler color flow mapping showed the presence of a coronary artery--left ventricular fistula. The normality of preoperative coronary angiography suggested that this fistula was created during peroperative left ventricular purging: the implantation of a needle through the right ventricle and interventricular septum. A iatrogenic lesion of a septal branch probably caused the communication between the left anterior descending artery and the left ventricle. Postoperative normalisation of the left ventricular end diastolic dimension, the absence of dilatation of the left main coronary on 2D echocardiography, the narrowness of the Doppler color jet and the absence of a significant end diastolic Doppler signal in the aortic isthmus indicated a fistula of small size and simple Doppler echocardiographic follow-up was decided upon.