Abstract: In a pressure-diecast light-alloy piston for internal combustion engines, which piston comprises shaped fibrous bodies which are partly embedded in at least one of the piston head, ring zone, piston pin bosses and skirt of the piston, which bodies comprise short ceramic fibers, lying in a common plane and in said plane having a random orientation, the improvement wherein the piston (1) is made of a high-temperature magnesium alloy, the piston skirt at least on its sliding surfaces has a chemically applied or electrodeposited metallic sliding layer (3) which has a thickness of about 10 to 30 .mu.m and a hardness of about 740 to 850 HV.sub.0.01, and the inside surface of the piston is coated with a thin plastic paint layer (2) or an anodized magnesium oxide layer.