Twenty-four children aged 2 months to 8 years (average: 3 years) with congenital coronary artery fistulae were studied. In 20 cases, the fistula presented with a continuous murmur: in 4 cases, pulmonary flow was increased to such an extent that it led to cardiac failure. Echocardiography and coronary angiography showed that the fistula originated from the left coronary artery or one of its branches in 13 cases and from the right coronary artery in 11 cases. All but one fistula, which drained into the left atrial appendage, drained into the right heart chambers (ventricle: 14 cases; atrium: 9 cases). Spontaneous regression after 9 years was observed in 1 case. The other children were treated: by surgery in 20 cases (1 external ligature and 19 open heart occlusions) with 2 residual shunts (including the case ligated) which had to be reoperated. Three children underwent percutaneous embolisation resulting in 1 failure and 2 successes. After an average follow-up of 6.5 years (5 months to 15.5 years), all patients were alive and doing well with normal resting and exercise ECGs, normal Thallium scintigraphy (5 cases) and normal left ventricular function on echocardiography. Selective control coronary angiography (14 cases) showed a reduction in fistula diameter from 10 +/- 3.7 to 4.5 +/- 1.2 mm (p < 0.0001). The authors conclude that all congenital coronary fistulae should be occluded, by percutaneous embolisation when the anatomical features are favourable. The other cases require surgical occlusion, the long-term results of which are very good.