As diameter of microvessel becomes smaller in end- to-side anastomosis, some problems in the maintenance of patency may accompany the process.Transverse and longitudinal venotomies were performed onto the femoral veins of rats, as recipient vessels, to create spaces for appropriate anastomoses with superficial eqigastric veins as donor vessels. The patency rates were assessed and compared on the 7th and 21 st days.In spite of differences in clamping and anastomosis times and number of sutures, the patency rates have been observed as 100 % in both groups, in the early postoperative period. But, in the late postoperative period, the results have differred in patency rates in favor of transverse venotomy group.This method, similar to the studies about micro- arterial anastomosis, can be considered as an appropriate technique of end-to-side microvenous anastomosis in clinical practice, because of its high patency rate, reduced operation time and decrease in the number of sutures.