This study was performed to determine the risk factors associated with increased body mass index (BMI) in 672 heavy industry men workers. Subjects were examined in March, 2010 to September, 2010 in Gyeongnam province. Height, weight, systolic blood pressure, and diastolic blood pressure were measured. And fasting blood glucose, total cholesterol, HDL-cholesterol, LDL-cholesterol, and triglyceride levels were measured by Olympus AU 680, and their BMIs calculated. Age, smoking statue, and alcohol drinking of the workers were surveyed by questionnairs. The mean total cholesterol levels were $190.06{\pm}36.62mg/dL$, HDL-cholesterol $53.65{\pm}11.92mg/dL$, LDL-cholesterol $104.28{\pm}30.31mg/dL$, triglyceride $151.11{\pm}99.53mg/dL$, and fasting blood glucose $96.92{\pm}19.53mg/dL$. Mean systolic blood pressure was $126.08{\pm}13.78mmHg$, and diastolic blood pressure $71.88{\pm}10.45mmHg$. Subjects were categorized into two BMI groups, BMI ${\geq}23$ and BMI ${\leq}22.9$. The subjects with BMI of 23 or above had significantly higher levels of LDL-cholesterol, systolic blood pressure, and triglyceride, with lower levels of HDL-cholesterol. BMI showed the highest level at the age of thirties, increasing with age. BMI of smokers was higher than BMI of non-smokers, not showing a link between alcoholics and non alcoholics. In conclusion, age, systolic blood pressure, and HDL-cholesterol are mostly relevant to the increase of BMI in this study.