Galactooligosaccharides (GOSs) are the non-digestible carbohydrates that are composed of 3-10 or longer molecules of galactose and the terminal glucose molecule. These are considered as prebiotics owing to their various health benefits, and therefore is the major focus of research. These are generally synthesized by the catalytic activity of the glycoside hydrolases (GH) utilizing lactose as a substrate, which results in the mixture of GOSs differing in their degree of polymerization. Different microbial glycoside hydrolases have been used for the production. Moreover, to improve the production, different biotechnological strategies have been applied, such as use of immobilized enzymes or recombinant enzymes. Thus, this review discusses the different prospects of GOSs production and its purification techniques.