Spinal epidural lipomatosis is an uncommon condition in which unencapsulated fat accumulates within the epidural space. We report a case in a 74-year-old obese patient who had been taking prednisone (10 to 20 mg per day) for 3 years to treat pseudomyalgia rheumatica. Intermittent radicular claudication and low back pain were the presenting symptoms. Magnetic resonance imaging showed epidural lipomatosis extending from L2 to S1. Spinal epidural lipomatosis is probably an underdiagnosed complication of long-term glucocorticoid therapy. Cases diagnosed early can be managed conservatively, whereas later on major surgery is unavoidable.