In this study, we successfully report an intimate ternary blend system of polycarbonate (PC)/poly(methyl methacrylate) (PMMA)/poly(vinyl acetate) (PVAc) obtained by the simultaneous coalescence of the three guest polymers from their common gamma-cyclodextrin (gamma-CD) inclusion compound (IC). The thermal transitions and the homogeneity of the coalesced ternary blend were studied by differential scanning calorimetry (DSC) and thermogravimetric analysis (TGA). The observation of a single, common glass transition strongly suggests the presence of a homogeneous amorphous phase in the coalesced ternary polymer blend. This was further substantiated by solid-state C-13 NMR observation of the T-1rho(H-1)s for each of the blend components. For comparison, ternary blends of PC/PMMA/PVAc were also prepared by traditional coprecipitation and solution casting methods. TGA data showed a thermal stability for the coalesced ternary blend that was improved over the coprecipitated blend, which was phase-segregated. The presence of possible interactions between the three polymer components was investigated by infrared spectroscopy (FTIR). The analysis indicates that the ternary blend of these polymers achieved by coalescence from their common gamma-CD-IC results in a homogeneous polymer blend, possibly with improved properties, whereas coprecipitation and solution cast methods produced phase separated polymer blends. It was also found that control of the component polymer molar ratios plays a key role in the miscibility of their coalesced ternary blends. Coalescence of two or more normally immiscible polymers from their common CD-ICs appears to be a general method for obtaining well-mixed, intimate blends. (C) 2004 Wiley Periodicals, Inc.