Background It is commonly assumed that patients with chronic low back pain are less active than healthy individuals. There has been a recent increase in the number of studies published comparing the physical activity levels of patients with chronic low back pain and healthy individuals. Objectives The aim of this systematic review was to determine, based on the current body of evidence, if patients with chronic low back pain have a lower level and/or altered pattern of physical activity compared with asymptomatic, healthy individuals. Data sources The electronic databases Embase, Medline, ISI Web of Knowledge, Cinahl, Sport Discus and Nursing and Allied Health were searched from the beginning of each database until the end of December 2009. Review methods Studies which compared the level and/or pattern of physical activity of patients with chronic low back pain and healthy controls were included. The quality of the included studies was assessed using an assessment tool based on the Newcastle-Ottawa Scale. The scale was modified for the purposes of this study. Results Seven studies were included in the final review. Four studies recruited adult patients (18-65 years), two studies examined older adults (≥65 years) and one study recruited adolescents (<18 years). Pooled data revealed no significant difference in the overall activity level of adults or adolescents with CLBP, however there is evidence that older adults with chronic low back pain are less active than controls. The results suggest that patients exhibit an altered pattern of physical activity over the course of a day compared to controls. Major methodological limitations were identified and are discussed. Conclusion There is no conclusive evidence that patients with chronic low back pain are less active than healthy individuals. Based on a limited number of studies, there is some evidence that the distribution of activities over the course of a day is different between patients with chronic low back pain and controls.