Three types of hydrogels obtained by electron beam irradiation and gamma ray irradiation, homopolymers of acrylamide (pAAm type), co-polymers of acrylamide-natrium acrylate (pAAmNa type) and homopolymers of natrium acrylate (pNaAc type) are presented. The effects of radiation absorbed dose and swelling medium nature upon the swelling degree and mechanical strength of these types of hydrogels are also discussed. Their proper physical characteristics can be well controlled by chemical composition of the solution to be treated by electron beam irradiation and by a suitable adjustment of the radiation absorbed dose. The best values obtained for the mechanical strength and swelling degree in distilled water for these hydrogels are, respectively: 25 kPa and 10 g/g for pAAmNa type, 6 kPa and 180 g/g for pNaAc type, 50 kPa and 8 g/g for pAAm type. These values are different from the ones obtained by gamma ray irradiation. Our experimental results proved that both the swelling degree and the mechanical strength depend on radiation absorbed dose level and swelling medium nature.