Sugars stabilise proteins against extremes of pH and heat denaturation. This was studied by means of density, ultrasonic velocity and viscosity measurements of the following systems (il) ovalbumin-phosphate buffer (pH 2.4, 5.2, 7.0 and 8.9) and (ii) ovalbumin-maltose-phosphate buffer (pH 2.4, 5.2, 7.0 and 8.9) systems as functions of concentration and temperature. The partial specific volumes (<()over bar>(0)), partial specific adiabatic compressibility (<()over bar>(s)), intrinsic viscosity, [eta] and shape factor, nu, were calculated for the said systems. The results obtained from such studies suggest that the stabilisation of ovalbumin occurs in the presence of maltose through strengthening of hydrophobic interactions.