Abstract: Lysine is an essential, economically important amino acid used as food and feed supplement. It has also some pharmaceutical applications in the formulation of diets with balanced amino acid composition and in amino acid infusions. Chemical, enzymatic and fermentation processes have been used to synthesize lysine. This review outlines the efforts of various researchers, which provide useful information regarding the fermentative production of lysine by bacteria. It also discusses different methods, including the development of new auxotrophic mutants and optimization of culture conditions used in order to improve the total yield and quality of lysine.