Patients with pulmonary arterial hypertension (PAH) often die from right heart failure or sudden cardiac death. Cardiopulmonary resuscitation (CPR) may be instituted in these patients but there are no data in the medical literature about the outcome of CPR in this group of patients. We conducted a retrospective multicenter international study on the frequency and results of CPR in patients with PAH. A total of 3,130 patients with PAH were treated between 1997 and 2000 in 17 referral centers in Europe and in the United States. During this period, 513 patients had circulatory arrest and CPR was attempted in 132 (26%) of these patients. Although 96% of the CPR attempts took place in hospitalized patients (74% in intensive care units or equally equipped facilities) and although there was only minimal delay between collapse and initiation of CPR, resuscitation efforts were primarily unsuccessful in 104 patients (79%). Only eight patients (6%) survived for more than 90 d; these patients had no residual neurologic deficit. Hemodynamics obtained within 3 mo before CPR did not show any significant differences between the survivors and nonsurvivors. Except for one patient, all long-term survivors had identifiable causes of circulatory arrest that were rapidly reversible. Our data indicate that CPR for circulatory arrest in patients with PAH is rarely successful unless the cause of the cardiopulmonary decompensation can be corrected.