Two research groups in both North and South America independently discovered that renin released a novel vasopressor agent. The Argentine group named it hypertensin, and called its plasma protein substrate hypertensinogen. The group from the United States named it angiotonin. In 1958, Braun Menendez and Irvine Page suggested that the peptide should be named angiotensin. The combined name eventually became commonly used to avoid linguistic confusion. Research scientists and physicians today acknowledge that studies of the renin-angiotensin system (RAS) have greatly improved our understanding of several diseases. Certainly, medical practice profited significantly from the synthesis and application of numerous pharmacological agents that antagonize either the biosynthesis or pharmacological responses of endogenously generated angiotensin II. Ultimately, discovery of the renin-angiotensin system led to many studies that resulted in therapies for vascular disease. This article briefly reviews research related to the discovery of angiotensin and indicates the importance of additional studies related to the RAS.