Background: In women with early ovarian cancer (EOC), comprehensive surgical staging is known to enhance ovarian cancer outcomes and requires specific surgical competence. Given that centralization of care remains a topic of continuing debate, a system of "guest operations" was introduced in the midwestern part of The Netherlands. During a guest operation a gynecologic oncologist participates in oncology surgery performed in the community hospital. Objective: This study was conducted to examine the effects of the presence of a gynecologic oncologist on the quality of staging, treatment, and survival in patients with EOC. Materials and Methods: All patients with a pathologically confirmed diagnosis of EOC between January 2000 and December 2009 were selected from a regional cancer registry. Surgical accuracy was checked on the basis of each patient's file, operative notes, and pathology report. Results: A total of 130 patients were included, of whom 15 were treated in the Leiden University Medical Center (LUMC) and 115 in eight regional community hospitals. If a gynecologic oncologist attended the operation, surgical staging was more often adequately performed, 81.1% versus 32.1% when a gynecologic oncologist was not present (p<0.001). Adherence to protocol was observed in 76.9% of operations when a gynecologic oncologist had been present, compared to 49.5% of patients who were treated by a general gynecologist alone (p=0.004). The 5-year disease-free survival was borderline significantly in favor of optimally staged patients, 75.1% in those who were not staged optimally versus 90.9% who were staged optimally (p=0.058). Conclusions: Guest operations deserve a distinguished place among the treatment modalities available to patients with EOC, because surgery by the most specialized and experienced surgeons contributes to better care. (J GYNECOL SURG 30:265).