Polycarbonate(PC)/ poly(styrene-co-acrylonitrile)(PSAN) blends were investigated by Raman and confocal Raman imaging spectroscopy, revealing the existence of two-phase (PC-rich and PSAN-rich) microdomain structure. This structure is coarser in blends with comparable component contents. During cold drawing the microdomains are strongly extended. As follows from polarised photoacoustic FTIR spectroscopy, a substantial orientation of PC chains occurs, as opposed to PSAN chains which orient only slightly. (C) 2000 Elsevier Science Ltd. All rights reserved.