Changes in serum CA-125 levels predict response to chemotherapy and survival in women with advanced epithelial ovarian cancer. Although often used to monitor for recurrence, randomized trial data do not suggest that treatment based on a rising CA-125 alone impacts prognosis if secondary cytoreduction is not under consideration. CA-125 surveillance may still provide benefits to patients who are likely to achieve a complete resection at secondary cytoreduction – assuming that early identification of recurrent disease based on a rising CA-125 level leads to a higher chance of complete gross resection. CA-125 surveillance also provides patients with useful information about prognosis and impending recurrence – regardless of whether this information impacts survival directly. As such, the routine use of CA-125 surveillance should be considered as an individualized option for patients based on disease characteristics and personal preferences.