Electric motors in electric vehicles (EVs) are susceptible to performance degradation due to heat buildup during operation. Excessive temperatures, especially above 60°C, can lead to reduced efficiency or even permanent damage. This study investigates the use of rotating heat pipes (RHPs) as a passive thermal management solution for electric motors. The RHPs are designed to be mounted on the motor shaft and tested at varying speeds and thermal loads. A slip ring system allows for real-time temperature data collection during rotation. The experimental data demonstrate that the RHPs enhance heat transfer performance while lowering thermal resistance by 30-66% relative to conventional stationary heat pipe. These outcome highlights the potential of RHPs as an effective passive cooling solution for electric motors, offering improved thermal efficiency without the need for extra energy consumption. © 2026 Published by IRCS-ITB.