Spiramycin is produced by Streptomyces ambofaciens. It is a mixture of compounds, similar in their elementary composition as well as in their physical, chemical, and bacterial properties. Its anti-bacterial spectrum includes mainly Gram-positive organisms and Neisseria. The fermentation medium of Streptomyces ambofaciens consists of corn steep liquor, glucose, CaCO3, NaCl, and MgSO4. Mode of action of spiramycin on microorganisms was represented in the review article. Spiramycin is used in animal nutrition, especially in poultry.