Arachidonic acid (AA) is a natural precursor of prostaglandins, thromboxanes, leukotrienes, prostacyclins, and a large group of C20 compounds which are of intrinsic medical interest. At present, the only source of AA is animal tissues. However, it is present in several microorganisms. This review describes the production of AA by microorganisms and its recovery and the potential of microorganisms as a source of AA.