The use of waste materials from road scrapping, called reclaimed asphalt pavement (RAP) and steel slag aggregates becomes more and more popular in road maintenance and road reconstruction. Those materials can replace and reduce the amount of virgin materials needed in the mixing process. In this research, the optimum bitumen content (OBC) of Marshall specimens has to be determined firstly, before the samples for resilient modulus test were prepared. The UMATTA equipment was used to determine the resilient modulus of each sample, which consist of: original mixture i.e., without slag and RAP materials, and the mixture with RAP and slag. The results showed that the mixture with RAP and slag materials has the higher resilient modulus, compared to the original mixture, and the most impactful parameters for the results are bitumen modulus, percentage of RAP materials, slag materials and void in mixture.