Concrete is one of the most important materials used in the construction industry. Researchers continuously seek to improve its mechanical properties and performance through the incorporation of nanomaterials. Nano-silica is considered one of the promising materials that has demonstrated effectiveness in enhancing concrete properties due to its extremely small particle size and large specific surface area, which enable it to significantly influence the microstructure of cement paste. This study aims to evaluate the effect of incorporating nano-silica into concrete mixtures on the strength and durability of concrete. Different percentages of nano-silica are used as a partial replacement for cement or as an additional material, while maintaining the other concrete mixture components as constant as possible to ensure accurate comparison of the results. Concrete specimens are prepared and tested after different curing periods, such as 7 and 28 days, to determine the extent of improvement in their mechanical properties. The effectiveness of nano-silica is mainly attributed to its ability to fill the microscopic voids between cement particles and binding materials, resulting in a denser internal concrete structure and reduced porosity. Furthermore, nano-silica reacts with the calcium hydroxide produced during cement hydration to form additional calcium silicate hydrate gel (C-S-H), which is the primary compound responsible for the strength development of concrete. The study focuses on evaluating compressive strength, splitting tensile strength, and flexural strength to determine the influence of nano-silica on the ability of concrete to withstand different types of loads. In addition, durability properties are investigated through water absorption, water permeability, and resistance to the penetration of harmful substances. Reducing concrete porosity and permeability can contribute to improving its long-term performance. The expected results indicate that incorporating appropriate percentages of nano-silica can improve concrete strength and durability by enhancing its microstructure, reducing internal voids, and promoting the formation of C-S-H compounds. However, excessive nano-silica content may cause particle agglomeration and increase water or superplasticizer requirements, potentially affecting concrete workability and final properties. Therefore, determining the optimum nano-silica replacement or addition percentage is an important aspect of this study. The significance of this research lies in the potential development of concrete with enhanced mechanical performance and durability through the application of nanotechnology in construction materials. This can contribute to improving the quality of concrete structures, reducing maintenance requirements, and extending their service life. Moreover, the use of nano-silica may provide advanced solutions for developing more efficient and sustainable construction materials. In conclusion, the incorporation of nano-silica represents a promising approach in the development of concrete technology due to its ability to improve the internal microstructure, mechanical properties, and durability characteristics of concrete. Determining the optimum dosage and investigating its influence on various properties are essential steps toward utilizing this technology in engineering and construction applications.