Discitis is a rare complication of disc operation. During a 10-year-period 1100 patients were operated for lumbar disc herniation and only eight patients developed postoperative discitis. The symptoms began 3 weeks after the operation and the most prominent clinical feature was back pain with muscle spasm. The sedimentation rate was highly elevated but the body temperature was slightly elevated for only a few days. Typical radiographic findings were narrowing of the affected disc space and end-plate resorption 3-4 weeks after the initial symptoms. In the early phase, CT showed hypodense disc material in the affected disc space, which may be the first radiological sign of discitis.