Mucosal surfaces of the body provide a universal entry portal for all known and emerging infectious pathogenic microbes. Therefore, it seems that special vaccination strategies are needed for vaccines that can hinder the entry capability of pathogenic microbes through the mucosal surfaces. Lactic acid bacteria are widely used in the food industry and are presently applied as delivery vehicles in many biological investigations. Among these bacteria, Lactococcus lactis is considered as a promising candidate for mucosal live vaccines to be used as an antigen delivery vector. This is an attractive alternative and a safer vaccination strategy against the pathogens, compared to other conventional methods. In this review, we summarized the applications of L. lactis as a mucosal vector of vaccine delivery for heterologous expression of proteins and its applications in biotechnology.