The aim of the present paper was to study the filmogenic capacity of Amaranth flour. The films were obtained in a casting process using glycerol as plasticizer. The influence of the glycerol content, pH, temperature of heating process and drying temperature and relative humidity on mechanical and barrier properties were evaluated. The effect of these variables was analyzed according a 2((5-1)) fractional experimental design that allowed the selection of significant factors: glycerol content, pH and process temperature. These then were used in a full factorial design. Solubility and mechanical properties were measured to obtain the optimal processing variables and casting solution formulation. The biofilms presented a yellowish color, moderate opacity, and high flexibility but low tensile strength. Nevertheless they showed less oxygen and water permeability than other protein and polysaccharide films. (C) 2004 Elsevier Ltd. All rights reserved.