The miscibility of blends of a polyarylate (PAr) with poly(trimethylene terephthalate) (PTT) was investigated in the whole composition range by DSC measurements. With the exception of the 90/10 composition, which was fully miscible, the blends showed partial miscibility, and contained a nearly pure PTT phase and a PAr-rich phase with 18% PTT. (C) 2004 Wiley Periodicals, Inc.