Epoxy-clay nanocomposites have recently gained considerable attention due to their interesting physical, thermal and mechanical properties. These properties, however, depend on a number of parameters such as the clay type, clay modifying agent, polymer matrix and the adopted mixing process. In the current work, epoxy-clay nanocomposites were prepared from Araldite GY6010 CRS and Nanomer I.30E nanoclay using different sonication (mixing) periods (5 to 60 minutes) and different concentrations of clay (2 to 5%wt). The effect of sonication time and clay loading on the tensile and hardness properties of the resulting nanocomposites were investigated. The results showed that the ultimate strength and fracture strain of the nanocomposites were below that of the neat epoxy, but the elastic modulus was generally enhanced by the addition of the nano-clay content. Increasing the sonication time enhanced the tensile strength on the expense of reducing the modulus of elasticity. Hardness of the nanocomposites did not show significant change with either the addition of clay or processing under different sonication times.