Poly(methylthiomethyl methacrylate) (PMTMA) is miscible with poly(p-vinylphenol) (PVPh) as shown by the existence of a single glass transition temperature in each blend. Fourier transform infrared spectroscopy, solid-state C-13 nuclear magnetic resonance spectroscopy, and X-ray photoelectron spectroscopy show that miscibility arises mainly from interactions between the hydroxyl groups of PVPh and the thioether sulfur atoms of PMTMA. Measurements of proton spin-lattice relaxation time in the rotating frame, T-1 rho(H), reveal that each of the blends has one composition-dependent T-1 rho(H), indicating that the blends are homogeneous on a scale of about 3 nm.