In flexible pavements, both heavy vehicle loads and seasonal temperature changes can influence rheological and mechanical properties of asphalt mixtures. Pavements designed and constructed for heavy-duty traffic under extreme weather conditions generally require engineered asphalt cement modification. Depending on the required types of improvement, proper modifier(s) should be introduced to improve properties. Recently, nano-materials with small sizes of 1-100 nm have been introduced as potential asphalt modifiers. These particles, with their high surface area, reveal unique bulk, surface, and colloidal properties. Based on previous studies, the addition of nano-clay, nano-carbon, and nano-silica can improve rheological properties of asphalt and consequently, mechanical properties such as tensile strain, flexural strength, and elasticity. Previous studies suggest that nano-clay, although not widely used as asphalt additives, has the potential to enhance the low temperature properties and performance of asphalt cement. This research is focusing on the rheological properties of asphalt cement modified using two different nano-clay materials. The mechanical performance of asphalt mixes containing nano-clay modified binders at different temperatures has also been compared with unmodified asphalt mixes.