The effects of pelivic irradiation may be seen mainly in the perirectal area related with the irradiating field. It is important to differentiate the postirradiation change from the recurrency or residual tumor ofcervical cancer in the clinical prognostic view of the patient. The prominent postirradiation changes may be difficult to differentiate from the recurrency or residual tumor of cervical cancer. The author analysed the CT findings of 35 patients who had received radiation therapy of cervical cancer at Inje University Seoul Paik Hospital. The radiation changes were compared with pre, and postirradiative CT findings in sequential follow-up course. The results were as follows: 1. Significant changes could be observed at least 3 months after irradiation. 2. Postirradiation changes include: Symmetrical thickening of perirectal fascia 28 cases 77% Increased perirectalfat 26 cases 75% Fibrous connection between sacrum and rectum 20 cases 57% Widening of presacral space 14 cases 42% Irregular thickening of rectal wall 5 cases 14%