Effect of amount of red mud and processing method on the tensile and impact properties of polymers were investigated when the red mud was added as a filler to polypropylene (PP), low density polyethylene (LDPE) and PP/LDPE blend. Especially in case of PP, increase in the tensile strength, elongation at break and absorbed energy was observed when extrusion was carried out more than two times. Tensile strength showed a very remarkable increase when master batch was used in comparison with simple multiple extrusion. In case of LDPE, 10% addition of red mud resulted in the increase of tensile modulus and impact strength, while 20% addition caused a decrease in the same properties. Addition of 5% EVA could reverse this trend. Addition of 20% red mud to PP/LDPE blend gave a decrease in impact strength but 5% EPR compatibilizer could improve the impact properties. Above results showed that the processing method is a very important factor in the utilization of red mud as a plastic fillers and master batch is one of the very effective way of red mud addition.