The relation between the dispersed phase particle size and blend composition has been examined for blends of nylon 6 and styrene/ acrylonitrile copolymer (SAN) over a wide range of compositions that traverse the phase inversion points for simple binary blends and those reactively compatibilized by the addition of imidized acrylic polymer (IA) or styrene/acrylonitrile/maleic anhydride terpolymer (SANMA). Nylon 6/SAN blends can be considered as a simpler version of industrially important polyamide (PA)/ABS blends; therefore, this study is useful for the better understanding of diminishing dispersed phase particles for PA/ABS blends with compatibilizers