A cross-sectional study was conducted for detecting the risk factors and to propose an effective control program for occupational low back pain. The subjects were 1,665 male production workers employed at a steel factory and a welding material manufacturing factory. The data were collected by a self-reported questionnaire and a medical examination with a rehabilitation specialist for ten days in September, 1997. The contents of the questionnaire were as follows: general characteristics, physical characteristics, employment status, type of work, working environment and the experience of low back pain. The number of cases with symptoms of occupational low back pain were 321, so the point prevalence was 19.3 persons/100 persons. The number of cases with a history of occupational low back pain for one year were 554, so the one year period prevalence was 33.3 persons/100 persons. The point and one year period prevalences of occupational low back pain showed no significant differences in age, marital status, educational level and body mass index. The point and one year period prevalences of occupational low back pain showed no significant differences in alcohol drinking, smoking, stretching exercise and regular exercise. The point and one year period prevalences of occupational low back pain were significantly higher in the unsatisfied group than the satisfied group(p < 0.01), However, no significant differences were found among tenures and shift work. The point and one year period prevalences of occupational low back pain were significantly higher in the lifting of heavy materials group than the nonlifting group(p < 0.01). However, no significant differences were found among posture of the waist and the working posture. Through the multivariate logistic regression, significantly associated factors with occupational low back pain were found to be dissatisfaction with job(point prevalence: OR=1.78, 95% CI: 1.21-2.61; one year prevalence: OR=1.76, 95% CI: 1.26-2.47), lifting of heavy materials(point prevalence: OR=1.94. 95% CI: 1.44-2.61: one year prevalence: OR=2.17, 95% CI: 1.70-2.77) and tenure(point prevalence: OR=1.03. 95% CI: 1.01-1.06: one year prevalence: OR=1.02, 95% CI: 1.00-1.05).