The purpose of this study was to determine the relationship between plasma C-reactive protein (CRP) and body mass index (BMI) in elderly Korean men. A review of routine health examination records were done. Out of 671 eligible elderly men, who had their routine health examination in 2001 at a Health Promotion Center of a university hospital, 367 subjects were included after excluding inflammatory conditions. Subgroup analyses were performed on those who did not smoke and exercised regularly. Body composition, blood pressure, blood samples and radiologic examinations including chest radiography and abdominal ultrasound were obtained from each subject. Age, BMI, current smoking, regular exercise, WBC count, HDL-cholesterol, gamma glutamyl transferase were independently associated with logCRP. BMI subgroups according to the Asia-Pacific guideline did not show any difference in CRP level from each other by ANCOVA (p>0.05). However, BMI groups subdivided according to our criteria showed an association with CRP; the CRP level was lowest in the group of BMI between 18.5-19.4 and showed significant difference from BMI group of the highest BMI group (>or=29.0). Since elevated CRP levels are associated with higher risk for cardiovascular disease, lower BMI (18.5-19.4) levels may be advised for healthy elderly men in Korea.