The use of thrombolytic agents in the treatment of postoperative pulmonary embolism presents a dilemma to the surgeon. On one hand, postoperative pulmonary embolism usually occurs within 2 weeks of surgery. On the other hand, recent surgery is considered a contraindication for the use of thrombolytics. We developed a protocol for treating pulmonary embolism patients who have recently undergone surgery. Urokinase, at a dose of 2,200 U/kg wt, is injected directly into the clot via a catheter positioned in the pulmonary artery. This is followed by continuous infusions of urokinase at 2,200 U/kg wt/hr until the clot is lysed (up to 24 hrs). Simultaneously, heparin is administered peripherally at 500 U/hr. The level of serum fibrinogen is monitored every 6 hours and maintained at no less than 0.2 g/dL to prevent bleeding. Thirteen patients were treated for angiographically proven pulmonary embolism within 14 days of surgery. Complete lysis of every embolus was achieved, and no deaths or bleeding complications occurred. Two patients received inferior vena cava filters, and nine patients no longer needed chronic anticoagulants within 3 months after the embolic event.