Rationale: Outpatient treatment ofpulmonary embolism (PE) maylead to improved patient satisfaction and reduced healthcare costs. However, trials to assess its safety and the optimal method for patient selection are scarce. Objectives: To validate the utility and safety of selecting patients with PE for outpatient treatment by the Hestia criteria and to compare the safety of the Hestia criteria alone with the Hestia criteria combined with N-terminal pro-brain natriuretic peptide (NT-proBNP) testing. Methods: We performed a randomized noninferiority trial in 17 Dutch hospitals. We randomized patients with PE without any of the Hestia criteria to direct discharge or additional NT-proBNP testing. We discharged the latter patients as well if NT-proBNP did not exceed 500 ng/L or admitted them if NT-proBNP was greater than 500 ng/L. The primary endpoint was 30-day adverse outcome defined as PE- or bleeding-related mortality, cardiopulmonary resuscitation, or intensive care unit admission. The noninferiority margin for the primary endpoint was 3.4%. Measurements and Main Results: We randomized 550 patients. In the NT-proBNP group, 34 of 275 (12%) had elevated NT-proBNP values and were managed as inpatients. No patient (0 of 34) with an elevated NT-proBNP level treated in hospital (0%; 95% confidence interval [CI], 0-10.2%), versus no patient (0 of 23) with apost hoc-determined elevated NT-proBNP level from the direct discharge group (0%; 95% CI, 0-14.8%), experienced the primary endpoint. In both trial cohorts, the primary endpoint occurred in none of the 275 patients (0%; 95% CI, 0-1.3%) subjected to NT-proBNP testing, versus in 3 of 275 patients (1.1%; 95% CI, 02-3.2%) in the direct discharge group (P = 0.25). During the 3-month follow-up, recurrent venous thromboembolism occurred in two patients (0.73%; 95% CI, 0.1-2.6%) in the NT-proBNP group versus three patients (1.1%; 95% CI, 0.2-3.2%) in the direct discharge group (P = 0.65). Conclusions: Outpatient treatment of patients with PE selected on the basis of the Hestia criteria alone was associated with a low risk of adverse events. Given the low number of patients with elevated NT-proBNP levels, this trial was unable to draw definite conclusions regarding the incremental value of NT-proBNP testing in patients who fulfill the Hestia criteria.