Fiber reinforced polymer (FRP) bars have gained popularity for replacing steel reinforcing bars in reinforced concrete (RC) structures due to their corrosion resistant nature, high strength, and low weight. However, when it comes to estimating the interfacial shear transfer strength, engineers are still trying to understand the FRP contribution. Research on this topic has shown that FRP bars are able to transfer shear across different concrete interfaces such as monolithically cast concrete with a pre-existing crack and cold joint applications, but the shear strength of FRP-reinforced interfaces is lower compared to that of steel-reinforced interfaces with the same amount of reinforcement. This paper presents a quantitative review of experimental studies of specimens with FRP interface reinforcement reported in the literature. The influence of selected variables, including interface condition and reinforcement quantity, is evaluated in terms of the shear transfer strength. The behavior of FRP-reinforced interfaces is compared to that of steel-reinforced interfaces, highlighting their similarities and key differences. Available design models for predicting the shear strength of FRP-reinforced interfaces are discussed and assessed. Finally, research gaps are identified and discussed.