In recent years, the use of waste products in cement-based building materials has been increasing. In this study, it is aimed to examine the usability of recycled asphalt waste, which is used as a waste product, as well as its behavior under the influence of high temperature. For this purpose, physical, mechanical properties and high-temperature behavior of mortars containing recycled asphalt aggregate (RAP) were determined. Standard mortar mixing ratios were taken as fine aggregate/cement/water = 3/1/0.5 and RAP was used as fine aggregate at 0%, 25%, 50%, 75% and 100% ratios. All series are produced in 40 × 40 × 160 mm size. On the 28th day, physical properties such as water absorption, porosity, capability coefficient, ultrasonic pulse velocity (UPV) were determined as well as mechanical properties. To examine the high-temperature behavior of the produced mortar samples, they were exposed to temperatures of 200 °C, 400 °C, 600 °C and 800 °C in a high-temperature oven. By determining the bending and compressive strengths after heating, the strength losses between pre-heating and post-heating were determined. For the use of RAP in mortars, 25% is recommended considering both physical and mechanical properties and the effect of high temperature.