ABSTRACT Acrylonitrile–butadiene–styrene (ABS) shows excellent impact resistance and good stiffness. The incorporation of thermoplastic elastomer into ABS may consist in an interesting approach to further improve the toughness of ABS, in addition to tuning its compatibility with reinforcements. Blends of ABS and styrene–butadiene–styrene (SBS) were obtained by extrusion from different types of ABS with different SBS contents. The results showed that morphology and mechanical behavior of ABS/SBS blends depend strongly on the composition and characteristics of ABS matrix. An increase in elongation at break and slight decrease in modulus could be observed by increasing SBS content. ABS/SBS blend possessing good dispersion of rubber particles with sizes ranging from 0.1 to 0.8 μm of rubber particles exhibited the better performance of the impact resistance, whereas blends showing a predominance of relatively large particles resulted on poorer mechanical properties. These results suggest that viscosity and composition of ABS matrix play a significant role on the dispersion and coalescence of the dispersed phase during mixing. © 2018 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2019, 136, 47075.