This study assessed the prevalence of low back pain (LBP) and investigated risk factors for LBP among seafood processing factory workers in Thailand including migrant workers. The subjects were Thai and Myanmar workers in the typical seafood processing factory. A cross-sectional study was carried out with a self-administered questionnaire. Prevalence of LBP, general characteristics, life style, and working condition were investigated. The associations between LBP and risk factors were estimated by multiple logistic regression models. Of 254 workers, 165 completed the questionnaire. Half of these workers were Thai, the others were from Myanmar. The point prevalence of LBP was 28.5%. Risk factors for LBP were age over 40 yr, poor health status, history of back injury, twisting posture at work, and slipping on wet floors. The results suggest that health promotion should focus on working conditions rather than individual life style in order to prevent LBP. Furthermore, greater attention to other risk factors such as history of back injury and perception of health status after regular health check up, especially in older age groups may be needed.