Saffron ( Crocus sativus L.) is a monocotyledonous herbaceous triploid plant that produces the most expensive spice in theworld. Its main constituents, crocin, picrocrocin, and safranal, are responsible for color, taste, and aroma, respectively. Thesaff ron plant produces a red-colored spice that is important in pharmaceutics, cosmetics, perfumery, and textile dye-producingindustries. Iran produces almost 90% of the total world production. The saff ron market is expected to grow by 12.09% inthe forecast period 2020 to 2027. This paper reviews the current knowledge about the taxonomy, geographical distribution,reproductive biology, chemical composition, therapeutic and traditional uses, and agro-technology of the world’s mostexpensive spice crop, saff ron.