In this study, the effect of carbon black (CB) additive obtained from waste tires on the workability properties of asphalt at medium and high temperatures was investigated. For this purpose, modified asphalts were obtained by adding CB in proportions of 5, 10, 15 and 20% by weight to pure asphalt with penetration class B 160/220. The physical properties of pure and modified asphalts were determined by penetration, softening point and ductility tests. In addition, penetration index (PI) values, which are considered as a measure of the temperature sensitivity of the binders, were also calculated. Then, volatile matter loss in pure and modified binders at high temperatures was determined by the rolling thin film oven test (RTFOT), and the workability properties of the binders were determined by the rotational viscometer (RV) test. According to the physical test results, it was observed that the hardening tendency of the binders increased and the penetration class changed to B 100/150 with the addition of CB. In addition, it was observed that the temperature sensitivity of the binders decreased with the CB additive, and the optimum rate was 15%. According to the RV results, it was observed that the workability of the binders decreased and the mixing and compaction temperatures increased with the addition of CB.