Obesity is associated with impaired endothelial function assessed as flow-mediated vasodilation (FMD), the procedure of which involves transient brachial artery occlusion and following reactive hyperemia. Acute aerobic exercise can improve FMD. This study examined the effects of repeated FMD procedures and acute aerobic exercise on FMD in obese young men. Upper arm cuff inflation of 200 mmHg for 5 min and subsequent deflation was induced at 0, 1 and 2 h to examine effects of repeated FMD procedures on FMD in obese subjects, as well as in lean controls. To observe the combined effects of FMD procedures and acute exercise on FMD in obese subjects, 45 min moderate exercise was performed immediately after FMD procedure at 0 h, with the procedure repeated at 1 and 2 h. The results showed that, after repeated FMD procedures, FMD in obese subjects increased from 5.9 +/- A 4.0% to 6.5 +/- A 3.2% and 8.4 +/- A 2.8% (P = 0.017), whereas FMD demonstrated no changes in lean controls (P = 0.90). After repeated FMD procedures and exercise, FMD in the obese subjects increased from 7.3 +/- A 3.5% to 9.5 +/- A 4.0% and 11.0 +/- A 4.3% (P = 0.0004). The present findings demonstrate that both repeated FMD procedures and acute aerobic exercise improve FMD in obese subjects.