Between 1972 and 1990, 18 patients (median age 3 years, range 0.1-14 years) with coronary artery fistulae (CAF) were seen at this institution. Of the 16 patients without associated heart defects, two patients presented with congestive heart failure and the remaining 14 were asymptomatic. Fifteen patients had normal origin of two coronary arteries. Two patients had atresia of the proximal right coronary artery and, in one patient, the right coronary artery originated from the left main coronary artery. The QP/QS ranged between 1.0 and 2.8, with a mean of 1.4. Fifteen patients underwent operative closure without any deaths. One patient is being followed medically at present. Two patients showed spontaneous clinical improvement of CAF (complete closure in one and near complete in the other) and remained asymptomatic during a decade of follow-up. Review of the literature suggests operative closure of symptomatic and asymptomatic small CAF during childhood. However, the natural history of minute CAF remains unclear. In addition, symptoms from CAF may spontaneously improve with time.