Three patients with coronary artery fistula confirmed by coronary angiography and surgery were studied using two-dimensional and Doppler echocardiography. Two of these patients had left coronary artery-right ventricle fistula. The proximal dilatation of the coronary arteries was visualized in all three patients by two-dimensional echocardiography. The course of the dilated right coronary artery and left circumflex artery was demonstrated by two-dimensional echocardiography in two patients. We were able to detect the disturbed flow at the drainage site in one patient by using the conventional Doppler echocardiography. In conclusion, it should be emphasized that two-dimensional and Doppler echocardiography can be useful methods in diagnosing coronary artery fistula.