Objective. This retrospective, nationwide, observational study was designed to compare treatment in tertiary referral centers vs. regional hospitals on overall survival for patients with stage IIIC and IV ovarian cancer. Material and methods. The study took place in all gynecological departments in Denmark, involving a total of 1,160 patients with stage IIIC or IV ovarian cancer. Data were extracted for 2,024 patients with all stages of ovarian cancer recorded in the Danish Gynecological Cancer Database between 1 January 2005 and 31 December 2008. The main outcome measure was overall survival. Results. No difference was found between tertiary centers and regional hospitals with regard to age, body mass index, American Society of Anesthesiologists score or comorbidity. Patients in regional hospitals had poorer Eastern Cooperative Oncology Group performance status, i.e.1.0 vs. 2.0 (p= 0.005). Patients in referral centers presented more often with stage IIIC and IV disease, i.e. 59.7 vs. 51.7% (p <0.001). Patients with stage IIIC and IV disease in regional vs. tertiary hospitals had a higher rate of primary cytoreductive surgery, i.e. 89.5 vs. 82.5% (p= 0.004), a poorer rate of complete cytoreductive surgery following primary cytoreductive surgery, i.e. 13.9 vs. 25.2% (p <0.001), a lower rate of neoadjuvant chemotherapy, i.e. 5.5 vs. 13.4% (p <0.001), and more often underwent acute surgery, i.e. 17.0 vs. 9.2% (p <0.001). Patients treated in referral centers had better overall survival (p= 0.021). Treatment in a referral center was an independent prognostic factor for overall survival hazard ratio, 0.83 (confidence interval 0.70-0.98). Conclusion. Patients with stage IIIC and IV ovarian cancer benefit from treatment in a tertiary referral center.