The histopathologic changes of radiation hepatitis have been well described. The magnetic resonance (MR) appearance, however, has been described only in two case reports. We obtained serial MR scans of patients undergoing therapeutic irradiation for Hodgkins lymphoma to determine the time course of changes in signal intensity of the liver. We found an increased signal intensity of the irradiated portion of the liver on T2-weighted images. Changes first detected at 4 weeks following 3600 cGy to the abdomen returned to normal signal intensity within 60 days following completion of radiation therapy. One patient demonstrated a subtle increase in signal intensity of the irradiated region as early as 7 days after receiving 2000 cGy. Our results suggest that MR imaging is a useful noninvasive means of tracing the course of radiation hepatitis.