An experimental study is carried out in order to determine the thermal performances of a water-cooled heat pipe cooling system. An experiment rig is designed, fabricated and fully instrumented to test the cooling system prototype. The results show that the maximum heat transport capacity of the heat pipe increase with the water-cooling temperature; however, its overall thermal resistance decreases. Correlations for heat transfer in the evaporator and condenser sections are proposed. A model is also developed in order to determine the capillary limit as well as the heat transfer in the heat pipe. The model can predict the experimental results within-1.7 % and +7.9 % when estimating the capillary limit and underestimates the heat pipe overall thermal resistance within-17.8 % and-9.7 %; however, it overestimates the evaporator temperature within 4.4 % and 9.5 %.