Purpose of investigation: Primary peritoneal carcinoma (PPC) is histologically similar to ovarian serous carcinoma, but its biochemical features remain obscure. The authors investigated and compared clinical findings, treatments, and outcomes of patients with PPS and those with epithelial ovarian cancer (EOC) patients. Materials and Methods: The authors retrospectively reviewed data from 14 patients with PPC and 219 patients with EOC treated at the present hospital from January 2005 to December 2012, including demographic data, pathologic findings, treatments, and outcomes. Results: Patients with PPC were significantly older (62.6 ± 8.4 years) than those with EOC (56.3 ± 11.3 years) (p = 0.045). There was no significant difference in serum CA-125 levels. The five-year survival rates did not differ significantly between patients with PPC (61.1%) and those with EOC (60.3%; p = 0.78); nor between patients with PPC and those with Stage III serous EOC (43.8%; p = 0.40). Conclusions: Treatment strategies for EOC applied to PPC apparently led to similar survival patterns among the two patient groups. Cytoreductive surgery combined with pre/postoperative platinum-containing chemotherapy may be effective for PPC patients.