The rotor for an electric motor includes a central rotor shaft (2) and a permanent-magnetic rotor body fastened on the rotor shaft. The rotor body is provided with a casing (8) which is radially distanced to the rotor shaft (2). A first annular space, which is adjacent the casing (8) and which is molded out with a plastic (10) at least partly containing magnet particles, is formed between the rotor shaft (2) and the casing (8).