This retrospective study analyzes the complications and the problems developed during and after pedicle screw fixation in patients with spinal disorders and trauma. One hundred twelve patients were treated using the Cotrel-Dubousset pedicle screw fixation system for degenerative disease (57 patients), trauma (42 patients), infection (eight patients), and tumor (five patients) of the lumbar or thoracolumbar spine. The average age of the patients was 47 years and the average followup was 35 months. Forty-seven general complications were seen in 41 patients (36.5%). In addition, hardware failures were observed in 12 patients (10.7%), junctional problems were seen in five patients (4.5%), problems in the instrumented segments were seen in 39 patients (34.7%), and problems of balance occurred in five patients (4.5%). Although the rate of the reported complications was high, the final outcome of the patients was not affected significantly. Placement of the pedicle screws in the thoracolumbar and lumbar spine is a technically demanding procedure. It should be used by experienced and qualified surgeons who are aware of the pitfalls associated with its use.