The bidirectional Glenn (BDG) is frequently used in the staged surgical management of single ventricle patients. Controversy exists whether accessory pulmonary blood flow (APBF) sources should be left at the time of the BDG to augment systemic saturation or should be eliminated to reduce volume load of the ventricle. The present study was a retrospective review to assess the influence of APBF on outcome after the BDG.