The mechanical and microstructural properties of cortical bovine bone have been extensively studied due to the fact that its micro-structural components would significantly reflect the global mechanical behavior of the bone. The objective of this article is to study the elastic modulus and hardness of a bovine cortical bone, in both longitudinal and transverse directions by using nanoindentation technique. The moduli in the longitudinal and transverse directions were recorded as 16.23 GPa and 10.26 GPa, respectively. While the hardness readings in the longitudinal and transverse directions were 0.505 GPa and 0.387 GPa, respectively. According to the result shown, it is suggested that heterogeneous properties of the bone is assumed and the measurements of their properties are highly dependent on tissue types, anatomical location and bone mineral content distribution.