Over the past years, extensive studies have been conducted on concretes containing rice husk ash and recycled aggregate, which have shown the advantages of those concretes. Today, in most parts of the world, there has been a huge evolution in concrete technology to achieve concrete with high strength. Considering that the compressive strength of concrete is one of the most important mechanical characteristics of concrete and also one of the main parameters of concrete design, extensive research has been done by researchers to investigate the factors influencing the compressive strength of concrete. In this thesis, the physical and mechanical properties of concrete with rice husk ash and recycled aggregate have been studied. The results of this laboratory study show that the compressive strength of concrete containing 30% recycled aggregate and rice husk ash is higher than that of 40%. Also, the average 7-day compressive strength of concrete containing 30% recycled aggregate and rice husk ash is 288, and the average of 40% is 218.5, which indicates that the sample is more than 30%. The average 28-day compressive strength of concrete containing 30 The percentage of recycled aggregate and rice husk ash is 289. The average of 40% is 314, which shows that the 40% sample is more. Also, the 28-day tensile strength of concrete containing 30% recycled aggregate and rice husk ash with a water-to-cement ratio of 0.377 is equal to 39. The average of 40% is 42, which indicates that the tensile strength of the 40% sample is higher.