The influence of solvent on the development of crystallinity in a compatible poly(styrene-co-acrylonitrile) (SAN) and poly(vinyl chloride-co-vinyl acetate) (VYHH) blend has been studied by differential scanning calorimetry (DSC), optical microscopy, Fourier transform infrared spectroscopy (FTIR), and a wide angle X-ray diffraction method (WAXD), confirming the presence of crystallinity in the blend. The low temperature casting of the blends developed a considerable amount of solvent-induced crystallinity in one component of the blend, whereas the higher temperature casting of the blends and also the coprecipitated blends showed no sign of development of crystallinity in the blend. So, solvent retention during film formation was responsible for the observed crystallinity in one component of the blend. Copyright © 1996 Published by Elsevier Science Ltd.