This work deals with the characterization of a plasterboards based on baobab trunk fibers for thermal insulation in buildings. The aim of this study is, firstly, to evaluate the thermal insulating capacity of baobab trunk fibers and, secondly, to determine the thermophysical and mechanical properties of plasterboards reinforced with baobab fibers. The results indicate that the water absorption of plasterboards increases with increasing fibers content, while the thermal conductivity and density decrease with increasing fibers content. All plasterboards showed good thermo-physical and mechanical properties for thermal insulation of buildings.