Abstract: The process for the realization of door and window frames made of plastic material comprises: a step of providing a profiled element (1) made of plastic material for the realization of door and window frames; a step of providing a reinforcing element (8) made of metal material, the profiled element (1) having a containment seat (6) of the reinforcing element (8); a step of inserting the reinforcing element (8) inside the containment seat (6); a step of fixing the reinforcing element (8) to the profiled element (1) by means of fixing means (9) between at least a portion of the profiled element (10) and at least a portion of the reinforcing element (11); wherein the fixing step comprises a heating step of the portion of the reinforcing element (11) by means of electromagnetic induction means (12), the fixing means (9) being adapted to cooperate with at least one of the portion of the profiled element (10) and the heated portion of the reinforcing element (11) for the fixing of the portion of the reinforcing