Aluminum alloys are known for their good strength-to-weight ratio, making them a good candidate for many applications in the automotive and aerospace industries.1 However, many of these alloys begin to lose their mechanical properties around 200–250°C, and titanium alloys are used instead.2 Scandium was investigated as a potential alloying element to increase the mechanical properties of cast aluminum alloys at elevated temperatures. A novel Al-Sc alloy was cast, heat treated, and the elevated-temperature mechanical properties were determined. The addition of scandium to aluminum alloy 242.0 resulted in a significant change in the microstructure and an increase in the tensile strength at temperatures up to 220°C. The increase in high temperature strength was due to the presence of stable Al-Sc precipitates and enhanced solid solution strengthening.