A study was conducted to evaluate the outcomes of the bidirectional Glenn shunt technique performed off-pump. Between April 1999 and April 2001, 36 patients underwent bidirectional Glenn shunt, unilateral in 28 patients and bilateral in 8 patients, without using cardiopulmonary bypass. The patients consisted of 25 males and 11 females with a mean age of 5.7 +/- 5.4 years and a mean body surface area of 0.72 +/- 0.34 m2. Preoperative percutaneous oxygen saturation was 75% +/- 7%, and pulmonary arterial pressure was 14.3 +/- 3.6 mmHg. There was no operative mortality. Chylothorax occurred in 1 patient in the early postoperative period. All the other patients were discharged without complications. Mean arterial oxygen saturation at discharge was 92.7% +/- 4.0%. This shunt technique is easy to perform and is helpful in the early management of patients with a functionally univentricular heart. However, much remains to be learned about this unusual physiological system.