The solubility parameters of networks based on poly(glycidyl azide) (PGA) and poly(epichlorohydrin) (PECH) were determined via swelling experiments in a series of solvents. Because of having the same main chain structure, it was observed that PECH and PGA networks acquired the same solubility parameter value. This can be interpreted as the substitution of pendant (-N-3) groups for (-Cl) groups on PECH-diol main chain not having any marked effect on the solubility parameter value of PECH gel. The solubility parameters of these two polymers were also computed according to the group contribution method. A comparison of the experimentally determined solubility parameter of PGA and its calculated value implied that the pendant nitrogens are linked linearly to each other.