A prosthesis for a cardiac valve including prosthetic leaflets which are intended to functionally replace the native leaflets of a cardiac valve following the implantation of the cardiac prosthesis. The prosthesis also including a prosthetic member on which there are mounted the prosthetic leaflets and which is intended to take up a stable, predetermined functional configuration in which the prosthetic member and the prosthetic leaflets reproduce the functionally correct configuration for the purpose of the physiological replacement of the native cardiac valve. The prosthetic member is preconfigured so as to move gradually from an altered, temporary functional configuration, in which the prosthetic member has a deformed geometry with respect to the stable, predetermined stable functional configuration, to said stable, predetermined functional configuration.