Abstract The histopathological findings following microvascular repair of 105 arteries and 89 veins in Englishstrain rabbits are reported. The importance of (a) the accurate apposition of the vessel walls and (b) the avoidance of excesive medial necrosis is stressed. The process of subintimal hyperplasia is described and the importance of its role in the repair of small vessels is discussed. Previously, the new formation of elastin tissue has been considered pathognomonic of vascular disease. The appreciably slower rate of repair in veins is also reported. From these observations suggestions have been made with regard to improved technique of surgical repair.