The crystal structure and the morphology of poly(ethylene oxide) (PEO)-2-methyl resorcinol (MRES) supramolecular complexes are investigated by differential scanning calorimetry and wide-angle and small-angle X-ray scattering. Depending on the MRES content, two molecular complexes with different stoichiometries are observed. The first complex with a stoichiometry of 22 mol % MRES melts around 80 degrees C. This complex has a layered structure almost similar to the structure of the PEO-p-dihalogenobenzene intercalates. This complex results from the intercalation of MRES molecules between polymer layers. The second complex with a stoichiometry of 33 mol % MRES melts around 90 degrees C. Its crystal structure is dictated by the formation of a tight network of hydrogen bonds between host and guest molecules. In addition, depending on the experimental conditions, the growth of nonintegral-folded or integral-folded crystals of PEO-MRES complexes is observed from the small-angle X-ray diffraction curves. These different crystal morphologies are finally discussed in terms of the intermolecular interactions in these solid-state supramolecular assemblies.