Thromboelastography (TEG) is a laboratory assay utilized to evaluate hemostatic properties of blood, identify coagulopathy, and guide blood product administration. While the clinical use of TEG started in the care of surgical patients, the assay has now been incorporated more routinely in the care of the medical patient as well. In this review, we explore the evolution of TEG from the historical perspective of its inception to the current state of the art of the assay. The TEG procedure and its measurements are illustrated along with a table that summarizes recommendations from across the medical and surgical literature. After each section, we review salient learning points to provide the busy clinician with information that can be immediately integrated at the bedside. We conclude with a series of summary questions to check for comprehension and direct the reader to additional resources to improve their knowledge of TEG.