The effect of the introduction of poly(ethylene glycol)methacrylate (PEGMA) on structural, thermal and electrical properties of solid electrolytes based on poly(ethylene oxide) (PEG) and sodium thiocyanate, is investigated by means of calorimetric, mechanical, X-ray diffraction and conductivity measurements. PEO-PEGMA systems show in general a lower value of the glass transition temperature as compared with pure PEG. The crystallinity of the latter has been found to reach a minimum value at about 17% weight of PEGMA. In this situation it is possible to dissolve salt to a concentration chi = 0.051 at least, without formation of the crystalline complex. The ionic conductivity has been found to be almost two orders of magnitude larger than that of PEO-NaSCN systems.