The miscibility of a sodium alginate/poly(vinyl alcohol) blend in water was studied by viscosity, ultra-sonic velocity, and refractive index techniques at 30, 40, and 50degreesC. Using the viscosity data, interaction parameters mu and alpha were computed. Theme values revealed that the blend is miscible when the sodium alginate content is more than 50% in the blend. This was further confirmed by ultrasonic and refractive index methods. It was further observed that the temperature has only a marginal effect on the miscibility of this blend. (C) 2003 Wiley Periodicals, Inc.