The invention relates to medical technology and could be used in manufacturing artificial cardiac valves having one or more cusps made of a polymer composite. The method for manufacturing a cusp of an artificial cardiac valve, includes the steps of: manufacturing a casting mold, and molding a cusp from a polymer composite comprising 78 to 92% by weight of polyamide and 8 to 22% by weight of radiographic contrast medium dispersed therein. The polymer composite can comprise additionally fine acetylene black in amount of 1 to 2% by weight. The preferred radiographic contrast medium is barium sulphate. In one embodiment of the method, the casting mold is manufactured for the molding size 1 to 5% less than necessary, and the cusp is placed after molding into an anticoagulant solution and matured therein until expanding by 1 to 5%.