Natural, biosynthesized poly(gamma-glutamic acid) (gamma-PGA) was crosslinked using dihalogenoalkanes yielding hydrogels with various features. Crosslinking reactions of the polymer and swelling of the hydrogels were studied. Various reaction parameters, like temperature and catalyst content, were adjusted to give highest yields in the network production. Swelling of the hydrogels showed dramatic changes when varying experimental conditions such as the molecular weight of gamma-PGA, the nature and concentration of the crosslinker, and the solution used for the swelling (ionic strength, pH).