Folate, an essential vitamin, plays an important role in human life for the synthesis of nucleotides, vitamins and some amino acid. This vitamin cannot be synthesized by humans and must be obtained exogenously to prevent folate deficiency, neural tube defects (NTDs) and other related diseases. Folic acid, the chemically synthesized form of folate, is used for fortification and supplementation, but it can cause adverse effects such as vitamin B₁₂ deficiency in high intake. Therefore, novel methods to increase concentrations of naturally occurring folate in foods have grabbed the interest of researchers. The application of bacterial cultures in food fermentation is a novel strategy to increase “natural” folate levels. Dairy products, especially yoghurt, are an appropriate choice for bio-fortification of folate as they contain folate-binding protein which improves folate bioavailability. This study will review the folate production by probiotic bacteria in fermented milk based on various strains and culture conditions.