Study Design: Randomized parallel group comparative trial with a one year follow-up period. Objective: To compare in a population of chronic low back pain patients the effectiveness of a functional restoration program, including intensive physical training and a multidisciplinary approach, to an outpatient active physiotherapy program at one year follow-up. Summary of Background Data: Controlled studies conducted in the states and in northern Europe showed a benefit of functional restoration programs, especially on return to work. Randomized studies have compared these programs to standard care. A previously reported study reported the effectiveness at six months of both functional restoration and active physiotherapy, with a significantly greater reduction of sick-leave days for functional restoration. Methods: One hundred and thirty two patients with low back pain were randomized to eitner the functional restoration program (68 patients), or active individual therapy (64 patients). 1 patient did not complete the FRP program; 19 patients were lost to follow-up (4 in the FRP group and 15 in the AIT group). The number of sick-leave days in two year before the program was similar in both groups (180±135.1 days in AIT versus 185±149.8 days in FRP, P = 0.847)Results: In both groups, at one year follow-up, intensity of pain, flexibility, trunk muscles endurance, Dallas daily activities and work and leisure scores and number of sick-leave days were significantly improved compared to baseline. The number of sick-leave days was significantly lower in the FRP group. Conclusion: Both programs are efficient in reducing disability and sick-leave days. The FRP program is significantly more effective on reducing sick-leave days. Further analysis is required to determine if this over-weights the difference in costs of both programs. (R.A.)