A method for recycling polymeric materials, including a mechanical separation step (B), a first density separation step (C), an intensive cleaning step (E), and a second density separation step (G, V) is described. Additional separation steps, such as a third density separation step (M, W), and optionally a fourth density separation step (G_a, G_b). Further less essential steps such as wetting (A), grinding (D), air flow separation (K), drying (I), electrostatic sorting (Z) and optional sorting (Z_a) steps may also be carried out to achieve optimized and refined separation. Polymeric materials from refuse or crushed motor vehicles may thus be separated, and polyethylene, polypropylene, polystyrene and acrylonitrile-butadiene-styrene resins may be recycled.