N-Acetyl-d-neuraminic acid (Neu5Ac) and its derivates are a very important group of biomolecules because these sugars occupy the terminal positions in numerous macromolecules, such as the glycans of glycoproteins, and are involved in many biological and pathological phenomena. The synthesis and applications of Neu5Ac are attracting much interest due to the potential applications of this compound in the pharmaceutical industry, such as in the synthesis of the anti-flu drug zanamivir. In this review article, we discuss existing knowledge on the biotechnological production and applications of Neu5Ac and also propose some guidelines for future studies.