This work aims to investigate the physical and mechanical properties of sisal fiber and yarn of Moroccan origin. The cellulosic and non-cellulosic constituents of the Moroccan sisal fiber were identified by FTIR spectroscopy. The thermal properties were studied by thermogravimetric analysis. The hydrophilicity of the fiber was evaluated by the contact angle. The results show that the sisal fiber has a low thermal stability. The mechanical properties of the fiber analyzed by the Impregnated Fiber Bundle Test (IFBT) method show that the porosity of the impregnated yarns and the twist angle of the yarns influence the elastic modulus of the sisal fiber. The physical and mechanical properties of the manufactured sisal yarns were also characterized and analyzed. The obtained results reveal an interesting potential to use the Moroccan sisal fiber in development of bio-sourced composite materials.