Antimicrobial (AM) films comprising of thermoplastic starch (TPS) and a commercial aliphatic polyester blended with thermoplastic starch (APTPS) were prepared and their properties, release of AM agents, and AM efficacy was studied in laboratory media and on a real foodstuff (Cheddar cheese). The AM films were prepared using two techniques: (i) direct incorporation of AM agents (carvacrol, linalool or thymol) into TPS films via a compression moulding technique; and (ii) by application of a coating containing the AM agents onto the commercial APTPS films.