An experimental investigation of a highly efficient heat pipe heat sink was investigated, in which the interline region was optimized using sintered particles. The effects of condenser size, sintered particles, and forced air flow on the heat transfer performance were investigated experimentally. The experimental results indicated that the thin film evaporation could significantly increase the evaporating heat transfer coefficient and remove heat fluxes up to . In addition, a theoretical model capable of predicting the temperature drop occurring in this device was developed. The predicted performance was in good agreement with the experimental data and the resulting model can be used to assist in the design of high heat flux, heat pipe heat sinks.