Modern cryopreservation techniques have resulted in the clinical use of cryopreserved allograft heart valves and large diameter veins. In addition to these large vascular tissues, there is a need for small-diameter vascular allografts. We review our studies of cryopreserved rat microvenous allografts (1 mm diameter) in both the arterial and venous systems. The clinical utilization of cryopreserved allografts in reconstructive microsurgery and the potential problems associated with the use of allogeneic tissues will be addressed. Further applications for vascular cryopreservation in reconstructive surgery include small-diameter arteries, vascularized tissue flaps, and limbs.