Natural fibers, especially flax, jute and hemp fibers have gained more interest in the recent years due to their promising mechanical properties such as low cost, a high percentage of cellulose, easy availability, and biodegradability. This research work aims to determine the elastic and strength properties of flax fiber-reinforced polymer (FFRP), jute fiber reinforced polymer (JFRP) and hemp fiber-reinforced polymer (HFRP) composites. These composites were fabricated by hand lay-up technique with the fiber volume fraction limited to 50%. The material characterization was performed by conducting tensile and compressive tests as per ASTM standards to evaluate the elastic and strength properties such as tensile strength, Young’s modulus, compressive strength, and shear modulus. The mercerization process is also considered to treat the surface of the fiber with NaOH solution to identify the effects on the mechanical properties of the composite. From the obtained results, it is observed that the HFRP composites have better tensile and compressive strengths, whereas FFRP composites have better stiffness. The mercerization process on the fiber's surface has mixed effects on the elastic and strength properties of the natural fiber reinforced polymer (NFRP) composites.