PURPOSE: This study aimed to compare the acute effects of different types (treadmill vs. cycle) of moderate-intensity aerobic exercise on cerebral blood flow and cognitive function in young adults. METHODS: By a randomized crossover study design, ten participants were initially assigned to either treadmill exercise (TE; n=5) or cycle ergometer exercise (CE; n=5) and then they performed the other with seven-day wash-out period. Both exercises were implemented at the target heart rate corresponding to 70% of heart rate reserve for 30 minutes. Cognitive function was assessed by the Stroop Color-Word test at pre-and post-exercise. Cerebral blood flow was continuously monitored using near-infrared spectroscopy technique during rest, cognitive function test (CFT), and exercise. RESULTS: There was a significant group by time interaction in tissue saturation index (TSI) (p=.046). Post-hoc analysis presented that TSI at post-exercise CFT was higher than during exercise in TE (p=.02). In both exercises, TSI at pre-exercise CFT significantly increased compared to the resting value (p=.001). Cerebral oxyhemoglobin level was significantly increased during exercise and at post-exercise CFT compared to the resting value in both exercises (p<.001). The reaction time for certain cognitive tasks such as color, word with matched color, word with color interference, and color with word interference was improved after both exercises (p<.05). CONCLUSIONS: One-bout of moderate-intensity aerobic exercise acutely improves cerebral blood flow and cognitive function even in healthy young adults. Exercise types with the same intensity do not seem to make meaningful difference in the positive effects of aerobic exercise.