The relationship between the degree of lumbar lordosis and chronic low back pain (LBP) has long been speculated. It is postulated that prolonged sitting and sedentary lifestyle might change the degree of lumbar lordosis and cause LBP. The purpose of this study was to determine the effects of lifestyle, exercise, work setting, work intensity, and other demographic factors such as age, height, weight, and gender on the degree of lumbar lordosis and occurrence of LBP. Eight hundred forty subjects between ages 20 and 65 years were equally categorized into four groups: normal male, normal female, males with LBP, and females with LBP. A questionnaire was used to obtain information about the subject's lifestyle, work setting, level of exercise, and work-related physical activity. A flexible ruler was used to measure lumbar lordosis in all subjects. The average degree of lumbar lordosis for all subjects was 37° ± 13°. Females had greater lumbar lordosis (42° ± 15°) than males did (32° ± 10°). There was no significant difference in the degree of lumbar lordosis in subjects with different lifestyle (p = 0.97), level of physical activity (p = 0.36), work setting (p = 0.5), and with or without LBP (p = 0.28). The degree of lumbar lordosis was positively related with the number of pregnancies (p = 0.04, r = 0.25), age (p = 0.02, r = 0.1) and height (p = 0.0001, r = 0.31) and negatively related with weight (p = 0.04, r = 0.06) of the subjects. The likelihood of developing LBP was significantly higher in the subjects who had high work-related physical activity (p = 0.03) and those who exercised less often (p = 0.008). We found no significant relationship between LBP occurrence and the degree of lumbar lordosis (p = 0.68), work setting (p = 0.15), height (p = 0.08), weight (p =0.06), and age (p = 0.67) of the subjects. The degree of lumbar lordosis was not different between normal subjects and those with LBP. Lumbar lordosis was not affected by lifestyle, level of physical activity, or type of work setting. Although these factors have not been found to affect the degree of lumbar lordosis, some affected the occurrence of LBP. This finding indicates that the effect of these factors on LBP involves mechanisms other than changing the degree of lumbar lordosis.