A cross-sectional epidemiologic study about low back pain (LBP) reports and associated factors was conducted in two steel industries. A checklist was used to collect information concerning the health, the LBP history, the personal characteristics as well as the characteristics of the present and past working conditions. This checklist was filled by an interviewer during a free discussion with each worker; 618 blue collar workers participated in this study. Lumbar symptoms were 66%, 53%, and 25%, respectively, during the lifetime, the 12 months, and the 7 days before the interview. The multivariate logistic regression showed an association with two occupatinal factors: heavy efforts of the shoulders (OR = 1.62) and vehicle driving (OR = 1.15). The other characteristics of the working conditions such as physical workload, postures and movements of the trunk, or exposure to whole body vibrations were not associated with an increased prevalence of LBP.