A cross-sectional study with a self-administered questionnaire was conducted in order to examine the association between low back pain and smoking. The subjects analyzed were 6,891 adults aged 40-69 yr, who lived in a downtown district in Isesaki City, Gunma, Japan. There was a positive association between cigarette smoking and low back pain in men. The age-adjusted odds ratios of low back pain were 1.32 (95% confidence interval (Cl) 1.10, 1.57) for 1-20 cigarettes smoked per day and 1.40 (95% Cl 1.11, 1.76) for 21 or more. The association had similar strength after adjustment for alcohol consumption, physical exercise, body mass index, non-musculoskeletal disease, education, occupation, and whether living with parents, living with a child or children, or living alone. The multivariate odds ratios for low back pain were 1.29 (95% Cl 1.03, 1.62) for 1-20 cigarettes smoked per day and 1.36 (95% Cl 1.03, 1.80) for 21 or more. In conclusion, smoking was significantly related to low back pain, even if adjusted for other potential risk factors.