The rheological behaviour of composites based on acrylonitrile butadiene rubber (NBR) and high styrene resin (HSR) has been studied by using a Monsanto Processibility Tester. All the systems show pseudoplastic flow behaviour. It has been observed that the die swell increases with an increase in shear rate and decreases with an increasing wt % of HSR and temperature. The maximum recoverable deformation were calculated by assuming that the viscous response of the rubbers obeys the power law model, and elastic behaviour is described by Hooke's law. Correlating with the die swell, a linear generalized relationship was obtained between the die swell and the recoverable deformation. The principal normal stress difference was found to increase linearly with shear stress. The activation energy of the melt flow process decreases with an increase in both shear rate and HSR content.