BACKGROUND: Previously, a large epidemiological study has found that an increase in the serum triglyceride level is an independent risk factor of coronary artery disease and by treating it, the mortality due to coronary artery disease could be decreased. Our study is designed to analyze the serum triglyceride level in healthy adultg and to study various factors influencing the serum triglyceride level. METHODS: Study involved all patients who visited Seoul National University Hospital Health Promotion Center from May 1995 to Feb 1997. After a complete history and a physical examination, each participant answered a questionnaire involving sociodemographics, tobacco, alcohol, exercise, menstrual cycle and daily dietary contents. A blood chemistry was also drawn after 12 hours of fasting. We used analysis of covariance and multiple regression analysis to correlate triglyceride level with forementioned variables. RESULTS: Healthy 3,332 men and 2,986 women were statistically analyzed. The average triglyceride levels were 110.7mg/dl(geometric mean). Men at ,50's had the highest level of triglyceride. As women aged, their triglyceride increased. The proportion of participants in their 40's in men and 70's and over in women with triglyceride >200mg/d1, a value of clinical importance, was 19.0% and 18.4% respectively. The triglyceride level changed significantly according to BMI, exercise, physical fitness, alcohol, tobacco, blood pressure, uric acid and glucose. However, no statistically significant difference was found among diet thyroid function, income and region. For men, a multiple regression analysis revealed that the factors influencing triglyceride level, in decreasing order, were BMI, uric acid, tobacco, diastolic blood pressure, ALT and maximal oxygen uptake. However, for women, a similar analysis showed that BMI, systolic blood pressure, exericise, tobacco and age played a significant role(p<0.001). CONCLUSIONS: Serum triglyceride level was associated with correctable behavioral factors such as obesity, smoking, alcohol, exercise, and physical fitness. Among these factors obesity was the most related factor with triglyceride level.