Energetic valorization of thermoplastic wastes (High-density polyethylene (PE) and Polypropylene (PP)) to produce fuel using pyrolysis process is presented in this paper. HDPE and PP pyrolysis experiments were carried out in a lab-scale batch reactor under an inert atmosphere. Nitrogen gas was used as carrier before and during the experiments. The temperature was varied from 293 K to approximately 773 K. The viscosities of HDPE, PP and the mixture 50% HDPE & 50 % PP pyrolysis liquids are respectively equal to 1.08 cP, 0.67 cP and 0.8 cP. Its densities are respectively equals to 0.735, 0.751 and 0.759 (at 20 °C–30 °C). The high calorific value (the heating Value) is respectively equals to 45.235 ± 0.641 MJ/kg, 46.151 ± 1.33 MJ/kg and 45.393 ± 0.87 MJ/kg. The liquids obtained have approximately the same Kerosene (Coal Oil) high calorific value (46 MJ/kg). The flash points are respectively equal to 32 °C, 31 °C and lesser than 25 °C for the mixture. They are lesser than coal oil and Diesel values which are equal to 38 °C for Kerosene and between 38 °C and 58 °C for Diesel. The mixture of two polymers decreases the viscosity values comparing to coal oil (1.7 cP) and Diesel (3.35 cP).