Cigarette smoking has been shown to cause cutaneous vasoconstriction, a decrease in digital blood flow, impaired wound healing, and it was implicated as a cause of failure of microvascular anastomoses in replanted digits. The subject of the following study was to assess the effect of cigarette smoking on experimental microvascular anastomoses. Twenty Sprague‐Dawley male rats weighing 200 to 250 grams were divided into groups of ten. Both the experimental and the control groups were acclimatized to a Maddox/ORNL rat smoke inhalation exposure system for six days prior to operation. At this time they were anesthetized and bilateral femoral artery end to end anastomoses were performed by two surgeons, using standard microsurgical techniques. After a recovery period of 24 hours, both groups were started on a smoking/sham‐smoking regime for 12 to 13 days. After this time they were anesthetized again, the femoral artery anastomoses were checked for patency in vivo and excised for histological evaluation. Five cm3 of blood was drawn from each animal to be analyzed for the presence of nicotine and its metabolites, and the rats were sacrificed. All the anastomoses in both groups were patent at the time of exploration and no histological difference could be demonstrated between the two groups. The radioimmunoassay of nicotine and cotinine showed large amounts in the smokers, and none in the nonsmokers.