From January 1988 through to July 1994, 54 consecutive infants underwent an arterial switch operation for simple or more complex forms of complete transposition (concordant atrioventricular and discordant ventriculo-arterial connections). They ranged in age from 2 to 180 days. The Lecompte maneuver was performed in all. In the first 19 patients the harvested sinuses of Valsalva were filled with two separate patches of autologous preserved pericardium, while, in the last 35 patients, a wide pantaloon patch of tanned pericardium was employed. Five babies died within 30 days after the procedure (operative mortality of 9.2%, 70% CL 4–17%). Four survivors were found to have developed a significant supravalvar pulmonary stenosis from 1 month to 21 months postoperatively. Echocardiographic data showed a transpulmonary peak systolic gradient from 60 mmHg to 101 mmHg, with a right-to-left ventricular systolic pressure ratio from 0.65 to 0.9. Reoperation was performed from 8 months to 39 months after the arterial switch procedure. Supravalvar pulmonary stenosis was located at the level of the pulmonary trunk, extending distally in two cases, due to the growth of fibrous scarring tissue with partial calcification. The pulmonary valvar leaflets were involved in two cases. Relief of the obstruction was obtained by insertion of a wide shield-tailored polytetrafluoroethylene patch after making an inverted Y-shaped longitudinal incision in the pulmonary trunk between the anterior sinuses of Valsalva. No mortality occurred at reoperation. Early and midterm echocardiographic measurements showed the effectiveness of this technique, with only trivial or mild residual transpulmonary gradients.