Purpose: Ovarian cancer is the fifth most common cancer in women and the leading cause of death of all gynecological malignancies. Prognosis is determined by optimal surgical outcome (macroscopic complete resection) most commonly achieved in tertiary hospitals. We investigated whether tertiary versus non-tertiary hospital as the location of an initial diagnostic intervention for histological confirmation before cytoreductive surgery versus immediate primary debulking surgery impacts outcome in patients with advanced ovarian cancer. Methods: We analyzed 115 patients who underwent cytoreductive surgery at a German tertiary center: 60 patients underwent primary debulking surgery (PDS) and 55 patients had a diagnostic intervention for histological confirmation before debulking surgery (PHC). Results: Although there was no prognostic difference between the two subgroups, the median time to chemotherapy was longer in the PHC group (46 days) compared to the PDS group (26 days; p < 0.0001), equally seen comparing non-tertiary versus tertiary PHC groups (p: 0.0001), its impact confirmed in a multivariate analysis (PFS: HR: 1.03, 95%CI: 1.01–1.05, p: 0.007; OS: HR: 1.04, 95%CI: 1.02 –1.06, p: < 0.001) of the PHC group only. In total, 9/10 patients with port-site metastases after diagnostic laparoscopy were initially treated at non-tertiary hospitals, resulting in a lower PFS compared to patients without port-site metastases after laparoscopy (HR 0.21, 95%CI 0.06–0.733, p: 0.014). Conclusions: In conclusion, patients with ovarian cancer undergoing treatment solely at a tertiary center have some clinical benefits and improved outcome, given the shorter time to chemotherapy and potential impact of port-site metastases. This supports centralization of oncological treatment.