The complexation between poly(styrene-co-4-vinylphenol) (STVPh) and poly(ethyl methacrylate) (PEMA) due to hydrogen bonding in nonaqueous media was investigated by viscometry, laser light scattering (LLS), and nonradiative energy-transfer (NRET) fluorospectroscopy. The formation of STVPh/PEMA complexes in solutions strongly depends on the hydroxyl content in STVPh and the solvent used. The minimum OH content in STVPh required to form interpolymer complex aggregates is 9 mol % in. toluene and 22 mol % in 1-nitropropane. Such a large difference can be attributed to the two solvents having different abilities of accepting protons. Complete decomplexation of the STVPh/PEMA complexes in toluene can be realized by adding a small amount of tetrahydrofuran. LLS experiments reveal that the size of the complex aggregates depends on the blend composition and is a maximum at 1:1 base ratio. In addition, a new modified NRET procedure to monitor the interpolymer complexation is proposed in this paper.