Lactococci have almost become the E. coli of the lactic acid bacteria in terms of their genetic dissection and the transformation protocols which have made them amenable to genetic manipulation. These organisms are also among the most commercially exploited microbes being the principle starters in a variety of cheeses and other fermented dairy products. Over the last few decades, knowledge on the genetics and physiology of this bacterium has expanded greatly. This research has led to an increased understanding of gene regulation and protein expression in LAB with the result that superior starter cultures with commercially significant properties can now be constructed for the dairy industry. The purpose of this review is to highlight some of the milestones that have been achieved in the genetics of lactococci to date, and to demonstrate the potential for their genetic manipulation in light of recent innovations. The review will focus particularly on the beneficial industrial features associated with lactococci, and the subsequent development of food-grade molecular tools that have made possible the genetic engineering of these commercially-important bacteria (including the use of antibiotic-independent cloning and expression systems and the exploitation of conjugation as an efficient and safe approach for gene transfer).  In addition, selected examples will be used to highlight the potential of such molecular tool development.