A method of preparing a hydrogel wound covering from polymers by irradiation cross-linking is disclosed. An initial aqueous solution comprising at least 15% of a synthetic polymer cross-linkable by irradiation, at least one humectant, a natural polymer and water, is poured into a mould for shaping. Then the initial aqueous solution is allowed to mature in the mould during a period of time sufficient to obtain a semi-product having at least a content of 35% of synthetic polymer. Thereafter the semi-product thus shaped is removed from the mould and subjected to irradiation in order to cross-link and sterilize the semi-product. A hydrogel wound covering is also disclosed.