We evaluated the effectiveness of exercises and manipulation on pain, disability and sick leave in a systematic review of randomized controlled trials including patients with low back pain. Low back pain is commonly a self-limiting illness and most patients are free of symptoms within 14 days. On the basis of 11 studies, no additional benefits from exercises and manipulation were found in patients with acute complaints (0-4 weeks); thus, our results do not support guidelines that prescribe manipulation in the acute stage. One study found reduced disability and sick leave in the subacute stage (4-12 weeks) when patients were told that it was safe to move and this strategy was reinforced by a graded exercise program and visits to the workplace. Seven studies evaluated manipulation; the effectiveness was no better than other treatments or placebo. Based on seven studies in patients with chronic low back pain (> 12 weeks), there is strong evidence that exercises reduce disability and pain, but their effectiveness on sick leave is not documented. Four studies compared different exercise regimens, but found no evidence in favour of one particular method. The effectiveness of manipulation in patients with chronic pain is poorly documented.