Species from the genus Enterococcus have been used as probiotic for humans or animals, although this genus is not considered "generally recognized as safe" (GRAS). While enterococci are considered "positive" in food technology, isolates of this genus have emerged as opportunistic pathogens for the humans. The aim of this review is to summarize the characteristics that can determine the use of this genus as probiotics. According to the guidelines used to define the genus Enterococcus strains as probiotic a case-by-case evaluation of each potential technological strain is presented and research perspectives for using enterococci as probiotic is also discussed.