Intercorporal spondylodesis was performed for low back pain in 120 patients with spondylolisthesis and 192 patients with disc degeneration; the latter group had all had previous surgery. The operations were carried out with retroperitoneal access, in most cases using iliac grafts, and additional posterior screw fixation in a number of patients substantially shortened the postoperative immobilization time. Complications were one death from pulmonary embolism, one case of possible genital disturbance, four inconsequent infections and three vessel injuries. In each group less than 10% had an additional operation for early signs of non-fusion. In cases without concomitant spinal problems, the overall fusion rate was 95-98 per cent. Clinically, the spondylolisthesis group was superior with 75 per cent without low back pain and 95 per cent without radicular pain postoperatively versus 55 per cent and 77 per cent for the disc degeneration group.