A laser Doppler flowmeter was used to assess blood flow changes in habitual smokers, as compared with nonsmokers, where members of both groups were young and healthy. Acute and chronic effects of cigarette smoking were measured by using the cutaneous postischemic reactive hyperemia test. Basic flow was recorded in four sites: forehead, postauricular, forearm, and finger. Recovery time from reactive hyperemia was longer in habitual smokers than in nonsmokers. Peak flow during reactive hyperemia was significantly lower after smoking. Basic blood flow during smoking did not show significant variation in the sites tested. The authors conclude that skin microvasculature is influenced by acute and chronic effects of cigarette smoking in young subjects; they discuss some of the possible mechanisms and their implications.