STUDY OBJECTIVE Resuscitation measures should be guided by previous patient choices about end-of-life care, when they exist; however, documentation of these choices can be unclear or difficult to access. We evaluate the concordance of a statewide registry of actionable resuscitation orders unique to Oregon with out-of-hospital and emergency department (ED) care provided for patients found by emergency medical services (EMS) in out-of-hospital cardiac arrest. METHODS This was a retrospective cohort study of patients found by EMS providers in out-of-hospital cardiac arrest in 5 counties in 2010. We used probabilistic linkage to match patients found in out-of-hospital cardiac arrest with previously signed documentation of end-of-life decisions in the Oregon Physician Orders for Life-Sustaining Treatment (POLST) registry. We evaluated resuscitation interventions in the field and ED. RESULTS There were 1,577 patients found in out-of-hospital cardiac arrest, of whom 82 had a previously signed POLST form. Patients with POLST do-not-resuscitate orders for whom EMS was called had resuscitation withheld or ceased before hospital admission in 94% of cases (95% confidence interval [CI] 83% to 99%). Compared with patients with no POLST or known do-not-resuscitate orders, more patients with attempt resuscitation POLST orders had field resuscitation attempted (84% versus 60%; difference 25%; 95% CI 12% to 37%) and were admitted to hospitals (38% versus 17%; difference 20%; 95% CI 3% to 37%), with no documented misinterpretations of the form once CPR was initiated. CONCLUSION In this sample of patients in out-of-hospital cardiac arrest, out-of-hospital and ED care was generally concordant with previously documented end-of-life orders in the setting of critical illness. Further research is needed to compare the effectiveness of Oregon's POLST system to other methods of end-of-life order documentation.