The invention relates to thermoplastic molding compounds M comprising an antimicrobially active polymer component A containing 0.2 to 25 wt% polyguanidine A1 and one or more polymers A2 which carry one or more functional groups that can react with polyguanidine A1. The present invention also relates to methods for producing an antimicrobially active thermoplastic molding compound M comprising the extrusion of a polyguanidine component and polymer A2. In addition, the invention relates to molded parts and products which contain the thermoplastic molding compound M.