The authors present a new model for microsurgical training of venous anastomosis-namely, the dorsal penile vein of the rat. In 12 male Wistar rats weighing 220 to 290 g, the anatomy of the dorsal penile vein was studied by dissection and histology. Anatomic dissection studies revealed that the dorsal penile vein has an average diameter of 1.4 mm (range, 1.2-1.6 mm) without tendency to collapse. The vein could be dissected for an average segment of 25 mm without any branches, allowing easy dissection and approximator clamp placement. Comparison of its cross-section with that of the femoral vein histologically by light microscopy and scanning electron microscopy revealed a larger diameter and much thicker vessel wall with a prominent tunica media and adventitia. Based on the findings of the anatomic study, the dorsal penile vein anastomotic model was created in the rat. In 20 animals, the vein was divided sharply in its midsection and was anastomosed end-to-end using standard microsurgical technique. Results indicated a 100% patency rate immediately after the anastomosis and a 90% patency rate (18 of 20) 1 week after the procedure. This model offers the advantages of easy dissection without ligation of any side branches and a thick vessel wall without a tendency to collapse. Moreover, a major limb vein is not sacrificed. It is concluded that this new model may better simulate the clinical procedure of microvenous anastomosis because it presents similarities to human veins.