The Laboratory of Biomechanics of the Testing of Materials Institute of the Uruguayan Engineering School has ongoing biomechanical research for thr last 25 years. First about fixators employed in osteosynthesis and now also on the characterisation of biological tissues. A multidisciplinary group with physicians, chemists and statistical and mechanical engineers was integrated for that purpose. Research of biological tissues is carried out together with the National Organs and Tissues Bank. All materials are provided from cadaver donors. The objective is the biomechanical evaluation of tissues to be used as all allografts and the improvement of preservation methods. Elastic properties are determined for example in compression, tensile and bending tests. Sample extraction and preparation, equipments, testing procedures and some results for tendons and bones are detailed. Evaluation of fresh and cryopreserved vascular tissues is described and conclusions about their biomechanical difference between them are drawn.