Glucose-sensitive poly(methacrylic acid-g-ethylene glycol) (P(MAA-g-EG)) gels were synthesized by copolymerizing methacrylic acid and poly(ethylene glycol) monomethacrylate in the presence of activated glucose oxidase. The dynamic and equilibrium swelling behavior of the gels was examined as a function of pH. At low pH values the gels were in a collapsed state due to complexation between carboxyl and etheric groups. At high pH values, the gels swelled to approximately 20 times their dry weights. The glucose oxidase containing gels exhibited a higher rate of expansion than the non glucose oxidase containing gels as the former had fewer entanglements. Relaxation times were determined for the swelling and deswelling processes, and a time-dependent swelling behavior was obtained for partial swellings in different pH values.