Objective: The aim of study was to investigate the prevalence of health risk behaviors among employees in medium-sized factories, Songkhla province.

Methods: A cross-sectional survey was conducted using cluster sampling by proportional to size (PPS) in 20 medium-sized factories, including 1,000 subjects self-administered questionnaires. The period of study was June-October 2007.

Results: The questionnaire response rate was 91.3%. The prevalences of health risk behavior was: 23.3% hazardous drinking, 24.2% smoking, 50.4% unsafe sex, 59.9% not wearing a helmet when driving a motorcycle, 54.4% not wearing a safety belt when driving a car, 14.7% driving motorcycle or a car after drinking alcohol, 16.3% substance abuse, 53.4% lack of exercise, 11.1% inappropriate stress management. Gender was significantly associated with hazardous drinking, smoking, wearing a seat belt when driving and lack of exercise. Age was significantly associated with wearing a seat belt when driving. Education level was significantly associated with smoking, wearing a seat belt when driving and lack of exercise. Income was significantly associated with hazardous drinking, smoking, wearing a seat belt when driving and

substance abuse. Occupational class was significantly associated with hazardous drinking, wearing a seat belt when driving, substance abuse and inappropriate stress management.

Conclusion: The prevalence of health risk behaviors is high among employees in medium-sized factories. The findings of this study should be beneficial in health promotion programs.