Heart valve replacements have now been made for some years from human dura mater. While the clinical results have been encouraging there is a considerable lack of information on the mechanical properties of the dura mater and the effects of the glycerol treatment employed. This study revealed that glycerol provided an adequate preserving medium for periods of up to 12 days, with no significant changes in the mechanical properties of dura mater. A wide range in mechanical properties was observed with, for example, the tensile strength varying from 3.28 N/mm2 to 7.86 N/mm2. Although no age-related deterioration in human dura mater could be shown, the results do suggest that dura mater in excess of fifty years of age should be avoided in order to prevent the selection of poor quality material.