Glycidyl methacrylate derivatized dextran (dex-GMA) was synthesized by coupling of GMA to dextran in the presence of 4-(N,N-dimethylamino)pyridine using DMSO as an aprotic solvent and characterized by GPC, FTIR, and NMR. The structure of the product was established with H-1 and CH-COSY NMR. The degree of substitution, as determined by NMR, can be controlled by varying the molar dextran. Almost quantitative incorporation of GMA (>90%) was established. Hydrogels were prepared by radical polymerization of aqueous solutions of dex-GMA, using ammonium peroxydisulfate (APS) and N,N,N’N’-tetramethylethylenediamine (TEMED) as the initiating system. The polymerization rate, as determined by FTIR analysis, was dependent on the APS, the TEMED, and the dex-GMA concentration. By proper selection of the polymerization conditions, hydrogels could be obtained in which more than 95% of the methacrylate groups had reacted within 20 min.