Printed circuit board (PCB) technology, traditionally utilized in the manufacturing of electronic devices, has recently emerged as a cost-effective and scalable platform for the development of biosensors. Its widespread availability, standardized fabrication processes, and compatibility with modern microfabrication techniques make PCBs an attractive choice for integrating both sensing elements and electronic circuitry into compact, reliable, and low-cost biosensing systems. Also, PCBs offer key advantages, such as seamless integration with electronic components and microfluidic modules, which help reduce the overall device size and support compatibility with mass production. This chapter explores the fundamental principle of PCB technology, recent progress in the design and implementation of PCB-based biosensors, and provides insights into challenges and future direction in this field. In particular, the chapter highlights the transformative potential of PCB-based biosensors in medical diagnostics, including applications in point-of-care testing, real-time disease monitoring, and biomarker detection, emphasizing their role in enabling accessible, rapid, and accurate diagnostic solutions.