Background: The aim of this study was to investigate whether the 1-year survival rate of out-of-hospital cardiac arrest (OHCA) patients with malignancy was different from that of those without malignancy. Methods: All adult OHCA patients were retrospectively analyzed in a single institution for 6 years. The primary outcome was 1-year survival, and secondary outcomes were sustained return of spontaneous circulation (ROSC), survival to hospital admission, survival to discharge and discharge with a good neurological outcome (CPC 1 or 2). Kaplan-Meier survival analysis and Cox proportional hazard regression analysis were performed to test the effect of malignancy. Results: Among 341 OHCA patients, 59 patients hadmalignancy (17.3%). Sustained ROSC, survival to admission, survival to discharge and discharge with a good CPC were not different between the two groups. The 1-year survival rate was lower in patients with malignancy (1.7% vs 11.4%; P = 0.026). Kaplan-Meier survival analysis revealed that patients with malignancy had a significantly lower 1-year survival rate when including all patients (n = 341; P = 0.028), patients with survival to admission (n = 172, P = 0.002), patients with discharge CPC 1 or 2 (n = 18, P = 0.010) and patients with discharge CPC 3 or 4(n = 57, P = 0.008). Malignancy was an independent risk factor for 1-year mortality in the Cox proportional hazard regression analysis performed in patients with survival to admission and survival to discharge. Conclusions: Although survival to admission, survival to discharge and discharge with a good CPC rate were not different, the 1-year survival rate was significantly lower in OHCA patients with malignancy than in those without malignancy. (C) 2017 Elsevier Inc. All rights reserved.