OBJECTIVE: The aim of this study was to compare survival outcomes in two groups of patients with recurrent epithelial ovarian cancer (EOC) with initial recurrence detection by cancer antigen 125 (CA-125) elevation or imaging, and underwent secondary cytoreductive surgery (SCS). METHODS: A retrospective review of the medical records was performed on 99 recurrent EOC patients who underwent SCS at the Samsung Medical Center between January 2002 and December 2013. For follow-up after primary treatment, patients were routinely assessed by CA-125 levels every 3 months and computed tomography (CT) scan (or magnetic resonance imaging [MRI]) every 6 months for first 3 years, and by CA-125 every 6 months and CT scan (or MRI) every 12 months thereafter. RESULTS: The first recurrence was initially identified by either CA-125 elevation (n=41, 41.4%) or by imaging study (n=58, 58.6%). None of the patients showed the symptoms as initial sign of recurrence. There were higher percentages of extra-pelvic recurrence (87.8%) and multiple recurrences (78.0%) in the group diagnosed by CA-125 elevation. The proportion of no residual disease after SCS was comparably lower in the CA-125 group (22.0% vs. 72.4%). There were 19 cancer-associated deaths (19.2%) within a median follow-up period of 67 months. The group diagnosed by imaging had better overall survival from initial diagnosis (OS1), overall survival after SCS (OS2), progression-free survival after the initial treatment (PFS1) and progression-free survival after SCS compared to those of the CA-125 group (PFS2). CONCLUSION: EOC patients with recurrence initially detected by imaging study showed better survival outcomes than patients diagnosed by CA-125 elevation.