This chapter explores the evolving role of educated platelets in cancer diagnostics, leveraging next-generation sequencing (NGS) to analyze their RNA profiles. Over the past decade, the concept of educated platelets has emerged as a promising tool for clinical diagnostics and a source of novel insights into platelet biology. This chapter begins by introducing the physiological functions of platelets beyond hemostasis, highlighting their involvement in disease processes such as cancer. It then reviews key historical discoveries that positioned platelets as central players in cancer progression, setting the stage for their use as biomarkers. The chapter further examines how platelet RNA signatures, decoded through NGS, can serve as noninvasive biomarkers for detecting and monitoring cancer, distinguishing cancer patients from healthy individuals and those with noncancer diseases. Recent advancements in NGS technology and platelet RNA characterization are also discussed. Finally, the technical and clinical challenges of translating platelet RNA profiling into routine clinical practice are addressed. In summary, this chapter offers a comprehensive overview of the potential and challenges of platelet RNA profiling in cancer diagnostics and beyond.