Interpenetrating hydrogels with advanced stiffness were prepared from the iron-alginate and cross-linked poly(acrylamide). Multiple approaches were combined in order to prepare hydrogels with mechanical properties required for various biomedical applications. Final properties of these materials were studied in terms of their water content and elastic modulus. Special attention was paid to describe the relationship between final properties and the nature of alginate crosslinks (bivalent or trivalent ions). Parameters such as concentration and nature of the alginate, crosslinking density of poly(acrylamide) network, IPN formation procedure were studied and adapted for obtaining the desired materials. Compared to the simultaneous synthesis procedure, the two-step process was found to be absolutely necessary for effective miscibility of two highly crosslinked networks.