Objective To discuss the diagnostic value of multidetector CT(MDCT) on encapsulated fat necrosis after operation of abdominal cancer, and to investigate the key differences of CT features between encapsulated fat necrosis and postoperative recurrence or metastasis. Methods CT data of 36 patients with encapsulated fat necrosis after operation of abdominal cancer, who received CT in our hospital between Feb. 2012 to May. 2014 during followed-up were retrospectively analyzed, for the purpose of summarizing the CT characteristics. In addition, the clinical presentation, level of carcinoembryonic antigen (CEA) and CA-125 before and after operation were also taken into account, to explore the difference between encapsulated fat necrosis with tumor recurrence and metastasis. Results Among the 36 patients who had suffered from encapsulated fat necrosis after operation of abdominal cancer, 3 patients (8.3%) had 2 lesions and the rest of 33 patients (91.7%) had solitary lesion(a total of 39 lesions). All lesions showed non homogeneous masses consistent with the surgery path and surrounded by fat density ring and soft tissue density capsule. The size of most lesions (94.8%, 37/39) decreased over time. All lesions were found slightly enhancement in portal phase. Five patients with postoperative tumor metastasis, 31 patients had no recurrence or metastasis. Among the 5 patients who had postoperative tumor metastasis at the same time, postoperative CEA was positive in 3 patients, and postoperative CA-125 was positive in 2 patient. Among the other 31 patients who had no recurrence or metastasis, the levels of postoperative CEA and CA-125 of 1 patient were unknown, and the postoperative CEA and CA-125 of 27 patients in the rest patients(90.0%, 27/30) were both negative. Most of them had no special clinical symptoms, only a few (1 patient)patient had mild abdominal pain without other associated symptoms. Conclusion CT is a valuable tool to reveal and diagnose encapsulated fat necrosis in postoperative abdominal cancer. Combined CT findings(such as location, shape, and density) with CEA, CA-125, and clinical presentation, that is easy to differ it from postoperative recurrence and metastasis.