Background: We aimed to evaluate the complication rate in lumbar dynamic stabilization surgery of back pain in situations where conventional rigid implants could have been employed, with a follow-up of at least five years. Methods and Findings: Prospective study. There were included, all patients who underwent semi-rigid fixation of lumbar spine with the dynamic system during the period 2004 to 2010 in our department. Adverse events and reoperations were registered for analysis. In the study period, 144 patients were treated with the dynamic system and all of them were studied. Three screws were badly positioned. There were two (1.39%) infections, with need of surgical cleaning in one case. Out of 770 screws, the late complications included a radiolucency signal in 22 screws (2.86%) and four broken screws (0.52%). Nineteen patients (20.13%) needed reoperation due to pain or screw associated problems. Three (2.08%) of those cases received additional treatment due to segmental kyphosis, five (3.47%) due to flat back, five (3.47%) due to adjacent level stenosis, four (2.7%) due to lumbar pain complaints, and two (1.39%) due to a broken screw. Conclusions: The lumbar dynamic stabilization system is a fusion option for the treatment of degenerative spinal diseases. However it is not free of adverse events, the rates of implant failures, complications, and reoperations found in this study are similar to those described in the published literature about rigid systems.