In this study, mechanical characteristics of descending thoracic aorta were evaluated after preservation at +4 degrees C in EuroCollins solution or after programmed cryopreservation with 15% dimethylsulfoxide and compared to control segments. Arterial allografts were procured from multiple organ harvesting over a period of 2 years. All the segments were allowed to incubate in EuroCollins enriched antibiotics solution for 18 to 24 hr after harvest and were then tested as a control group or preserved at +4 degrees C in EuroCollins solution for 4, 7, 21, and 31 days or cryopreserved for 2 or 4 months. Each aorta was cut into parallel blades either in the radial or in the circumferential direction and mounted over a traction-compression apparatus for mechanical testing. Stress-strain characteristics indicated that no discernible differences were found between cryopreserved aorta and the control group. For those preserved at +4 degrees C a greater high strain modulus was noted for graft preserved for 21 and 31 days; however, this difference was not statistically significant. The authors concluded that cryopreservation did not alter the mechanical characteristics of arterial allografts procured from multiple organ harvesting.