With the aim of obtaining a route for polymeric blends, the behaviour of semi-crystalline poly(ethylene oxide) (PEG) and amorphous Novolak mixtures was studied. The crystallization of the semi-crystalline blend component at different compositions was evaluated by transmission microscopy with crossed polarizers. Infra-red data, thermal analyses and the determination of the Flory-Huggins parameter indicate both that the hydroxyl groups of Novolak are hydrogen bonded to the etheral oxygen of PEO and that the system is miscible. The miscibility of polymer-polymer blends of PEO and poly(vinyl phenol) (PVPh), through the component PEO and poly(vinyl phenol) (PVPh), which has a similar structure to Novolak, but higher molar weight, was also studied.