In this paper the barrier properties of a series of polyamides used for food packaging applications were analyzed. In particular, permeation of water through the investigated polyamides was studied and water diffusivity and solubility were evaluated as a function of water concentration. Water vapor sorption tests were performed at 25degreesC and at several water vapor activities on the four samples investigated. The obtained values were related to the macromolecular chain modification deriving from the introduction of different comonomers. (C) 2002 Elsevier Science Ltd. All rights reserved.