Details about custom built experimental set up to perform inflation tests at constant length on blood vessels are presented. Using this displacement controlled set up we can apply and measure pressures up to 100 kPa and axial loads ranging up to 100 N. The surface deformation is determined from tracking twelve markers in 3D space using 2 CCD cameras. Discarded vein tissue from patients undergoing Coronary bypass surgery were collected and stored at 4°C in normal saline and experiments were completed within 24 hours from harvest. Inflation tests at different axial stretch ratios on saphenous vein were conducted. Results show that the deformation of the vein is not axially symmetric. These suggest that the vein is inhomogeneous and/or residually stressed not only in the radial direction, but also in the circumferential and/or axial direction. The loading and unloading path is not different, suggesting that the vein is being subjected to non-dissipative process. Checking for the incompressibility condition, results show that the vein is compressible. These results have implications in the development of constitutive models for the vein.