Asphalt pavements are exposed to distresses especially cracks and rutting. These defects are encountered within the pavements as a result of deficiencies in mixture characteristics and increasable traffic loads. They occurred due to deficiency in asphalt binder and/or the mixture. This paper studies how to improve the asphalt mixture characteristics using Nano Silica (NS). The research includes studying the characteristics of the modified mixtures using NS. The tried NS contents are 3, 5, 7, 9 and 11% by bitumen weight. Marshall, Wheel Tracking, Indirect Tensile Strength (ITS) and Direct Compression (DC) Tests are used to evaluate the obtained characteristics. Results indicate that the most suitable NS content is 7% by weight of asphalt. Modifying the asphalt mixture by 7% NS increases the Marshall stability by 25%, decreases the flow by 19%, obtaining approximately the same unit weight and keeping the air voids percentage and other mix properties within the accepted limits. It also increases the DC value by 7%, increasing the ITS value by 2.7% and decreases the rutting depth by 40%. Generally, adding NS success in improving the characteristics of asphalt mixtures.