In this chapter, fundamental aspects and bioanalytical applications through the Surface Plasmon Resonance (SPR) sensors are addressed. A timeline is made regarding the configurations used in SPR instruments, highlighting the advantages and disadvantages of each one and what is expected in terms of applications. The focus is kept on the development of SPR-based biosensors for bioanalytical applications, discussing the main methodologies used up to date and recent strategies adopted to improve their analytical performances. Finally, an overview of the versatility and ability to integrate SPR-biosensors into lab-on-a-chip platforms for point-of-care applications is provided.