Linear and non-linear viscoelastic properties of Polypropylene (PP)/Polystyrene (PS) blends with organoclay (C20A) as a compatibilizer were investigated using dynamic oscillatory measurement, i.e., small amplitude oscillatory shear (SAOS) and large amplitude oscillatory shear (LAOS) tests. Four different mixing protocols were applied to probe the effect of mixing sequence on rheological properties. Moreover, each protocol was conducted at three mixing times, i.e., 1, 3, and 8 min, to investigate the effect of mixing time on final rheological properties. Final results revealed that mixing time had no significant effect on either the viscoelastic response of the simultaneously mixed blends or the PP+C20A/PS (PP and C20A mixed for 30 seconds and then PS added) blend. On the other hand, rheological properties of the PS+C20A/PP (PS and C20A mixed for 30 seconds and then PP added) blend significantly increased upon 1 min of total mixing time, whereas 3 and 8 min of mixing demonstrated almost the same results as their other blended counterparts. TEM pictures revealed migration of C20A particles from PS phase towards the interface with increasing mixing time.