PURPOSE: The objective of the study was to compare chiropractic management and medical management of low back pain of musculoskeletal etiology in a multispecialty group practice. STUDY DESIGN: The design was a retrospective cohort study in which the subcohorts were defined by source of low back pain care and identified before follow-up was complete. Data collection occurred at the end of the third month following their initial visits. One hundred and three chiropractic patients and 187 medical patients aged 16 or greater who had not been treated within the preceding month of their initial visit participated. MAIN FINDINGS: A greater proportion of chiropractic than medical patients perceived their treatment to be successful (RR = 1.91, 95% CI = 1.29, 2.82), had 0 days with low back pain during the week preceding the evaluation (RR = 1.60, 95% CI = 1.00, 2.59), and had no functional impairment due to low back pain after 3 months following their initial visit according to the Roland-Morris Disability Questionnaire (RR = 1.42, 95% CI = 0.81, 2.50). General health status was similar for both chiropractic and medical patients. CONCLUSIONS: Chiropractic care was at least as effective as medical care in reducing low back pain and functional disability due to low back pain. Chiropractic patients were more likely to perceive their treatment to be successful in reducing low back pain compared to medical patients.