The performance of fiber-reinforced polymers (FRP) in reinforced concrete (RC) constructions subjected to various environmental conditions is reviewed in detail in this research. The growing use of FRP in RC structures as a retrofit or reinforcing material has highlighted the necessity to comprehend its long-term performance and strength under various stresses from the environment. The literature on the impacts of variables including temperature changes, moisture content, UV rays, chemical exposure, and others on the mechanical characteristics and longevity of FRP in RC systems is rigorously examined in this review. The findings show that whereas fiber-reinforced polymer (FRP) materials often provide improved strength-to-weight ratios and corrosion resistance, their adhesion to the concrete matrix, mechanical characteristics, and overall durability can be negatively impacted by specific environmental factors. In order to maximize the usage of FRP in RC structures in a variety of environmental contexts, the study also identifies areas for future investigation and possible mitigating techniques. The results are intended to help practitioners, researchers, and designers make well-informed choices on the use and constraints of FRP in reinforced concrete structures.