The miscibility of Hydroxypropyl cellulose (HPC)/poly(ethylene glycol) (PEG) blends over an extended range of concentrations in water. The viscosity, ultrasonic velocity, and refractive index of the above blend solutions have been measured at 30• C. The interaction parameters such as Δβ and μ proposed by Chee and α proposed by Sun have been obtained using the viscosity data to probe the miscibility of the polymer blends. The values indicated that the blends were miscible when HPC content is more than 40% in the blend. The obtained results have been confirmed by the ultrasonic velocity and refractive index studies. The films of the blends were prepared by solution casting method using water as a solvent. The prepared films have been characterized by analytical techniques such as FTIR, DSC, X-RD, and SEM to probe the miscibility of HPC/PEG blends. The compatibility in the above compositions may be due to the formation of H-bonding between hydroxyl groups of HPC and etheric oxygen atom of PEG molecules.