Given that lactic acid bacteria (LAB) may face numerous hostile environmental conditions in nature, in food processing, and in the gut of man and animals, high resistance to stresses is either a chance in the case of beneficial biofilms or a challenge in the case of detrimental biofilms. Therefore, the need to control their formation in different environments requires unraveling the factors governing biofilm formation in LAB. Planktonic bacterial cells settle in a niche, adhere to a surface, produce an extracellular matrix yielding a growing 3D-mature biofilm that can be regarded as a bacterial building, and occasionally leave the biofilm to settle a new community in another more favorable niche. LAB biofilms also have potential in food/feed safety issues. The high cell density in LAB biofilms, the innocuousness of LAB, and the natural stress resistance of LAB biofilms have boosted attempts to exploit these bacterial communities in biotechnological issues.