To the best of our knowledge, there has been no research reported on the activity of nisin and natamycin, incorporated together in tapioca starch films, against a mixed culture present in refrigerated argentinian Port Salut cheese. Therefore, the aim of this study was to evaluate the effectiveness of natamycin and nisin supported in edible films to improve microbiological stability of refrigerated Port Salut cheese in relation to: a) the native microbiota, b) an external postprocessing contamination by a mixed culture (S. cerevisiae and L. innocua) on the surface of Port Salut cheese or on the surface of the covering film.