Heat pipes have emerged as passive devices that utilize the phase change of a working fluid to efficiently transfer heat between two surfaces. In recent years, they have gained considerable attention for thermal management in electronic devices. This study focuses on numerical investigations of a wickless heat pipe (thermosyphon) having its adiabatic section covered with Paraffin Wax Phase Change Material (PCM). Deionized (DI) water serves as the base fluid for comparison. The heat input to the heat pipe is varied from 10 to 50 W for 3640 s. It is observed that the heat pipe with paraffin wax achieved a maximum reduction of 55.79% in the evaporator wall temperature at 10 W. Additionally, the incorporation of paraffin wax led to a significant reduction, with the wall temperature along the evaporator being up to 10% lower compared to the non-coated heat pipe at 10 W. It is found that incorporating paraffin wax into the heat pipe enhances its ability to manage elevated thermal loads, indicating its effectiveness in electronic thermal management. Thus the utilization of paraffin wax is a valuable strategy for achieving efficient and reliable thermal control in electronic devices.