Probiotics are increasingly being used to treat and prevent urogenital infections. However, a critical assessment of their efficacy in major urogenital infections is lacking. We report the results of a systematic review to determine the efficacy of probiotics for prevention or treatment of three major urogenital infections: bacterial vaginosis, vulvovaginal candidiasis, and urinary tract infection. Using multiple computerized databases, we extracted data from clinical trials using a lactobacillus-containing preparation to either prevent or treat a urogenital infection. Of 25 included studies, 18 studies used lactobacillus preparations for treatment or prevention of urogenital infections and seven studies focused solely on vaginal colonization. Four studies included patients with vaginal candidiasis, five included patients with urinary tract infections, and eight included patients with bacterial vaginosis. One included several types of genitourinary infections. Overall, lactobacilli were beneficial for the treatment of patients with bacterial vaginosis. No clear benefit was seen for candidiasis or urinary tract infection. Studies were heterogeneous, with some limited by a small population size. In conclusion, the use of certain lactobacillus strains such as L. rhamnosus GR-1 and L. reuteri for prevention and treatment of recurrent urogenital infection is promising, especially for recurrent bacterial vaginosis. Scant data on the use of probiotics for urinary tract infection and vulvovaginal candidiasis precludes definitive recommendations. Further research and larger studies on types of lactobacilli strains, dosage of lactobacilli, optimal route and vehicle of administration are needed.