A program to alleviate chronic, major vessel thromboembolic pulmonary hypertension by pulmonary thromboendarterectomy was initiated at this institution in 1970. Multiple evolutionary changes in the diagnostic evaluation, surgical approach, and postoperative management have been implemented over the series of 323 thromboendarterectomies performed through March 1992. A sequence of five surgeons at the University of California at San Diego have performed these procedures, with the last 150 having been performed by one surgeon. We report here the changes in surgical approach developed over the last 150 cases and the results obtained. The operation involves a median sternotomy incision, the institution of cardiopulmonary bypass, and deep hypothermia with circulatory arrest periods. Incisions are made in both pulmonary arteries into the lower lobe branches. Pulmonary thromboendarterectomy is always bilateral, with removal of both organized thrombus and an endarterectomy plane from all involved vessels. The right atrium is routinely explored for atrial septal defects. Current techniques appear to allow more thorough revascularization and shorter circulatory arrest times. The surgical mortality of 8.7% over this span is below that previously reported from this and other institutions. Among survivors, the hemodynamic and functional results have been excellent. Surgically correctable chronic thromboembolic pulmonary hypertension likely remains underdiagnosed. The diagnostic, surgical, and postoperative management evolution provided by the coordinated team involved at this institution has established that pulmonary thromboendarterectomy can be performed with an acceptable risk and good hemodynamic and symptomatic results.