Poor behavior of concrete in tension has led to development of various methods, such as reinforcing and prestressing to improve its weakness. This has paved the way for its ever increasing structural and nonstructural applications. Since early 1960's, many research studies have been carried out and several industrial applications have been introduced. In recent years, its practical application is rapidly expanding and there are many applications in civil engineering works such as slabs, shelters, blast-resistance structures, airport runways, bridges and tunnels. Fiber reinforced concrete consists of the concrete and many DISTRIBUTION fibers. The use of fibers within concrete allows for more ductile behavior of concrete after cracking. Steel fibers are the most economical fibers and therefore are used more extensively than other fibers. They have large elastic modulus and ultimate strain and also enjoy sufficient ductility and high tensile strength. Additionally, to improve their behavior it is readily possible to produce them in various shapes and simply mix them with concrete. Polypropylene fibers are also one of the most frequently used synthetic fibers in concrete. This is mainly due to their relatively low production cost. They are normally used to control plastic shrinkage of concrete. In addition, even with small fiber content ratio, they can effectively reduce the fire risk for concrete. This study investigates the tensile strength of Fiber Reinforced Concrete (FRC) using steel and polypropylene fibers and considering various fiber contents. The volumetric ratios of steel fibers considered in this study are 0%, 0.3%, 0.6%, 0.9% and 1.2% while corresponding ratios for polypropylene fibers are 0%, 0.2 % and 0.4%. The test program included concrete splitting test for three different cylindrical specimens of 150´300mm, 100´200mm and 75´150mm and also flexural strength test on the prismatic specimens of 100´100´500mm. For all specimens, the tensile strength tests were carried out at the ages of 7 and 28 days. The same concrete mix design were used for all specimen so that to remove the effect of compressive strength variations on the test results. Concrete mix design includes 400 kg of cement, 947.8 kg of fine and 886.5 kg of coarse aggregates and 220.6 kg of water for each cubic meter of concrete. Water cement ratio was therefore 0.55. Type I cement was used for all tests, without any admixture. The compressive strength for the plain concrete, based on 150x300mm cylindrical specimens, was about 30 MPa. The test results show that the tensile strength of the cylindrical and the prismatic specimens notably increases, compared to normal concrete, by increasing the volumetric ratios of steel fibers. This is equally true for both 7 days and 28 days ages of concrete. However, the tensile strength of steel fiber reinforced concrete in splitting and flexural tests is not significantly affected by fiber ratios up to 0.6%. Additionally, test results indicate that the tensile strength of cylindrical specimens with 0.2% polypropylene fibers is increased at the ages of 7 and 28 days with respect to the concrete without fibers. But the specimens with 0.4% polypropylene fibers do not show significant increase of tensile strength and even there are evidences of reduced strength. With regards to prismatic samples, the results show that adding polypropylene fibers to concrete does not indicate a clear increase or reduction in tensile strength. Overall it is concluded that the effects of polypropylene fibers are very limited and more specifically it is almost negligible in the case of prismatic specimens.