Intermacromolecular complexation between poly(methyl methacrylate) and modified polystyrene (PS(OH)) with the introduction of strong proton-donating hydroxyl groups has been studied by means of viscometry and non-radiative energy transfer (NRET) spectrofluorimetry. By increasing the hydroxyl content in PS(OH), both the transitions from immiscibility to miscibility and then from miscibility to complexation in the toluene-cast blends can be realized. A stoichiometric complex (1:1 base ratio) forms when the hydroxyl content reaches a high (similar to 24 mol%) value. The NRET studies present evidence that in the complex, the polymer chains prefer to form unlike segment pairs rather than like ones. An apparent solvent effect on complexation is also observed for both solution and solvent-cast films