Over the last few decades, surface plasmon resonance (SPR) technique has been very promising for sensing applications. It involves light-matter interaction at the interface of the metal and dielectric. This technology is employed in physical, chemical and biological sensing applications. In this review, we present the principle of SPR, different configurations used for excitation of SPR, performance characteristics of a sensor and commercialization of the biosensors technology. A few applications of SPR as biosensors have also been reviewed in this article.