In this study, the thermal behaviour of bioadhesive polymer hydrogels, a mucin gel and their mixtures, was investigated using thermorheological and thermogravimetric analysis. Three poly(acrylic acid (PAA) polymers with different cross-linking status (Carbopol 974P, Carbopol 971P and Noveon AA-1) were selected on the basis of their good bioadhesive properties. Rheological scans from 10-90 degrees C were performed in the oscillatory mode. A marked increase in elastic modulus (G’) with temperature was detected above 50 degrees C in all mucin-containing samples, as opposed to the pure gels which showed a ’flat’ response. Thermogravimetric (TG) analysis (from 30-150 degrees C, at a rate of 8 degrees C/min) revealed variations of the pattern of water loss within the gels which corresponded to the rheological properties of the PAA systems. The thermal behaviour of the Noveon AA-1/mucin mixture did not show the same trends on mixing with mucin as did the Carbopol systems, indicating that the type of cross-linking agent (a tetrafunctional entity, as opposite to a bifunctional one in the Carbopols) may have an impact on the polymer interaction with mucin.