The phase behavior of poly(resorcinol phthalate-block-carbonate) (RPC) with engineering polyesters was investigated by using differential scanning calorimeter (DSC) and dynamic mechanical analysis. RPC was found to form miscible blends with poly(ethylene terephthalate) (PET), poly(butylene terephthalate) (PBT), and poly(cyclohexylmethylene terephthalate) (PCT), but was partially miscible with poly(1,4-cyclohexanedimethylene-1,4-cyclohexanedicarboxylate) (PCCD) in the melt state and below the melting temperature (T-m). The degree of melting-point depression indicates that the RPC is most miscible with PCT followed by PET and then PBT. Furthermore, with the help of empirical DSC data and the Nishi-Wang equation, the interaction parameters between RPC and PET, PBT, and PCT were quantified to be -0.36, -0.33, and -0.54, respectively. (C) 2008 Wiley Periodicals, Inc. J Appl Polym Sci 110: 2623-2633, 2008