We performed retrograde pulmonary arteriography by means of a pulmonary venous wedge injection in 10 patients with no demonstrable intrapericardial pulmonary arteries by "conventional" angiographic techniques. In all cases but one, the procedure demonstrated the feasibility of a further operation. No complications were observed. Retrograde pulmonary arteriography is an important additional method for determining the existence of surgically accessible pulmonary arteries when other techniques have failed.