Dynamic rheological properties of multiwalled carbon nanotubes-(MWCNTs) reinforced acrylonitrile butadiene styrene (ABS) composites prepared by micro twin-screw extruder with back flow channel (used for proper dispersion) are reported. Scanning electron microscopic and high-resolution transmission electron microscopic studies showed that the nanotubes were uniformly dispersed in the ABS polymer matrix. MWCNT forms a network throughout the polymer matrix and thus promotes the reinforcement. The rheological studies showed that (for 3 wt% of MWCNTs loading) the material undergoes viscous to elastic transition. At a higher MWCNTs concentration nematic gel-like phase is observed where both storage and loss modulus (G' and GaEuro(3)) are nearly independent of frequency. van Gurp-Palmen plot has been used to determine the viscoelastic properties. Dynamic intersection frequency has been used to correlate the rheological properties with different wt% of MWCNTs loading in ABS. Dynamic rheological measurements revealed the viscous-like (GaEuro(3) > G') behaviour at a lower MWCNTs loading (< 3 wt%) and elastic-like behaviour for higher loading (> 3 wt%).