Porous carbon materials have initiated a fast evolution in recent years because of their broad applications in various fields. However, the major challenge remains is control porosity, foaming agents, processing materials and good thermal and mechanical properties. In the present investigation, graphite foams with varying porosities (50–70%) were prepared using coal tar pitch derived semi coke as a carbon matrix and ammonium bicarbonate as a space holder, followed by carbonization and graphitization. The graphite foams were characterized in terms of structural, morphological, mechanical and thermal properties. The results reveal that graphite foams prepared trough space holder technique having excellent mechanical and thermal properties. The graphite foam is found to possess a thermal conductivity of 27.5 W/(m.K), compressive strength of 7.5 MPa, with a relative density (ρrd) of 0.41. The graphite foam is also found to be thermally stable and outperforming those metals, conductive polymers, and their composites. The newly developed graphite foams are promising for specific applications in aerospace electronic devices with excellent mechanical and heat dissipation characteristics, especially regarding extreme high temperatures.