This study presents a comprehensive historical and scientific analysis of the evolution of blood pressure measurement methods, dedicated to the 120th anniversary of the fundamental discovery made by Russian physician Nikolai S. Korotkoff. In 1905, he introduced the auscultatory method, which became a turning point in the development of cardiology and general medical diagnostics. The work covers more than two centuries of scientific progress—from the first invasive experiments by Stephen Hales in the 18th century, when blood pressure measurement required direct vascular access in animals, through the fundamental contributions by Bernoulli and Poiseuille that established the theoretical basis for understanding blood flow, to the development of the first non-invasive sphygmomanometers in the 19th century. Special attention is given to the contributions by Vierordt, Marey, and Riva-Rocci, whose developments created the technological foundation for Korotkoff’s discovery. A central part of this study is devoted to the detailed analysis of the revolutionary auscultatory method, which was initially met with skepticism by the medical society, but due to its simplicity, accuracy, and reproducibility, rapidly gained worldwide recognition and became the gold standard in clinical practice. From a modern scientific standpoint, the hemodynamic and biomechanical basis of Korotkoff sounds is described, explaining the physical nature of their appearance related to the transition of blood flow from laminar to turbulent during gradual arterial decompression. Advantages and limitations of the method are analyzed, considering it not only as a historical phenomenon but also as a current diagnostic tool retaining relevance in contemporary medicine. Particular emphasis is placed on the influence of the Korotkoff method on subsequent technologies for blood pressure measurement, including the oscillometric method, which dominates modern automatic and semi-automatic blood pressure meters but still requires calibration and validation against the auscultatory reference standard. The study highlights that Korotkoff’s discovery remains one of the most significant contributions of a Russian scientist to global medical science, preserving its practical and methodological value even 120 years after its introduction.