Randomized clinical trial comparing two interventions in employees sick-listed 3 to 16 weeks because of low back pain (LBP). To compare 1-year return to work (RTW), pain, disability and physical and mental health dimensions in subjects offered a hospital-based multidisciplinary intervention or a brief intervention. Previous studies in sick-listed employees with LBP have indicated efficacy of both brief and more comprehensive multidisciplinary interventions. However, it remains unknown, which is the more effective, and which elements are instrumental in furthering RTW, and improving health. The brief intervention comprised clinical examination and advice offered by a rehabilitation physician and a physiotherapist. In the multidisciplinary intervention, this intervention was supplemented with the expertise of a team and the assignment of a case manager who drew up a rehabilitation plan in collaboration with the patient and the multidisciplinary team. One-year RTW was estimated by data from a comprehensive national database of social transfer payments. Questionnaires were used to obtain baseline and 1-year data on Roland Morris disability score, LBP Rating Scale, SF36, and fear-avoidance. A total of 351 patients were included and randomized and 344 (98%) patients participated in all the consultations according to the study protocol. RTW was achieved by 125 (71.0%) participants in the multidisciplinary and 133 (76.0%) participants in the brief intervention group. The hazard ratio was 0.84 after adjustment for sex, age, smoking, compensation claims, disability score, and diagnosis (95% confidence interval [CI]: 0.65-1.08,P = 0.18). Multiple linear regression analysis displayed no differences in secondary outcomes, except for the mental health score (SF36), which was a little higher in the multidisciplinary intervention group than in the brief intervention group. Hospital-based multidisciplinary intervention may be no better than brief intervention to increase RTW and improve health in sick-listed employees with low back pain.