Hydroxyethylmethacrylate (HEMA) hydrogels were investigated for their suitability as a dural prosthesis. Poly-HEMA has many characteristics required for an artificial dural substitute: it is durable, flexible, easily prepared, inexpensive, easily sterilized and handled, easily shaped, and known to be chemically inert and nontoxic. Sheets made of plain HEMA were evaluated as dural substitutes in rats and rabbits after either craniotomy or laminectomy with durectomy. Histological evaluations of the prostheses and the underlying tissues were undertaken at various time points from 2 to 9 weeks postoperatively. There was minimal tissue response to the implanted HEMA gel in contrast to marked thickening of the overlying leptomeninges and cortical herniation in the control animals. It is concluded that HEMA gels fulfill the essential criteria for an effective dural substitute.