The results of the evaluation of zinc maleate and zinc anthranilate as thermal stabilizers for poly(vinyl chloride) (PVC) are reported in this article. Calcium stearate, diphenyl isodecyl phosphite, and epoxidized soya oil were used as costabilizers. Both zinc compounds showed good stabilizing performance in static and dynamic tests, particularly at low concentrations. The best results were obtained with zinc anthranilate.