A short review is given of the development of synthetic angiotensin. Also discussed are enzymic experiments, showing that production of the synthetic substance leads to valyl-5-angiotensin-II, in which all amino acids are completely in thel-configuration. Small amounts of diastereoisomers in intermediates, likel-valyl-d-tyrosyl-l-valyl-l-histidyl-l-prolyl-l-phenylalanine which was isolated and identified, are completely eliminated during the synthetic process. Valyl-5-angiotensin II-aspartyl-&bgr;-amides are very slowly hydrolyzed in aqueous solution to valyl-5-angriotensin II and a small amount of the heptapeptide, H·Arg-Val-Tyr-Val-His-Pro-Phe·OH, with negligible decrease in pressure activity of the solution.