Objective: Ovarian cancer has a high recurrent rate.A sensitive method for post-surgery monitoring is crucial for timely and appropriate management of the disease to reach a better survival.This study was designed to evaluate FDG PET in monitoring post-treatment ovarian canccr patients and its role in decision-making of a secondary cytoreductive surgery.Methods: Two groups of patients were enrolled from Feb.2003 to Aug.2010: Group 1 consists 67 patients who underwent 2~6 follow-up PET scans (175 studies in total) with an mean interval of 10 months.Other imaging reports and serum CA125 were used for comparison.Group 2 includes 17 patients who underwent 20 secondary cytoreductive surgeries after PET scans.The PET findings were compared with the surgery records site by site.Results: In group 1, PET is positive in 129 of 175 studies, 39 (30.2%) of them showed negative CA125; 2 studies were positive in CA125 while negative in PET, and one is proved to be a nonmalignant cystic space-occupying lesion.In 46 PET-positive studies with CT and/or MR results, all studies have showed abnormal in CT and/or MR while 23 new lesions were revealed in 14 (30.4%) studies in PET.All 53 PET-negative studies, including 10 with suspicious lesions of other image modalities, were confirmed free of lesions by 6 months follow-ups.In group 2, a total of 121 nodal lesions were confirmed after surgery.The preoperative PET reported 93(76.9%) of them; false negative lesions were in small size.For 18 studies with intubercular or military lesions, only 2 studies were positive in PET.None lesions were found in surgery in 9 PET-positive studies, which may result from physical uptake of bowls.Conclusion: FDG PET is an excellent method for monitoring post-treatment ovarian cancer, and may play an important role in the subsequent management of the disease, especially for guiding the secondary cytoreductive surgery.