tIn the present study, the results from thermogravimetric analysis (TGA), contact angle measurements,tensile tests, scanning electron microscopy (SEM) and atomic force microscopy (AFM) of polymer com-posites containing chitosan (Ch) and montmorillonite (MMT) with and without poly(vinyl alcohol) (PVA)are presented.Measurements of the contact angles for diiodomethane (D) and glycerol (G) on the surfaces of chitosanfilms, Ch/MMT and Ch/PVA/MMT, were made and surface free energies were calculated. It was found thatthe wettability of the chitosan/MMT or Ch/PVA/MMT composite films decreased relative to the wettabilityof chitosan. The microstructure of unmodified polymers and their composites, as observed by SEM andAFM, showed particles that are relatively well dispersed in the polymer matrix. The TGA thermogramsand mass loss percentages at different decomposition temperatures showed that the thermal stability ofthe binary composite slightly decreases upon the addition of PVA. The film mechanical properties suchas tensile strength, Young’s modulus and tensile strain at break depend on the composition and variednon-uniformly. Both composites possessed a tensile strength and Young’s modulus of 27.6–94.3 MPa and1.5–3.5 GPa, respectively. The addition of PVA to the composite led to a reduction in tensile strength byapproximately 40%.