H2O2-producing commensal lactobacilli inhibit N. gonorrhoeae in vitro and clinical data suggest they are associated with reduced risk of gonorrhea. Here we pre-colonized mice with Lactobacillus crispatus and then challenged them with N. gonorrhoeae to measure the effects of H2O2-producing lactobacilli on gonococcal infection. We found no difference in the duration of infection or number of gonococci recovered from untreated mice and mice colonized with L. crispatus. A gonococcal catalase mutant and a catalase, cytochrome C peroxidase mutant exhibited greater susceptibility to L. crispatus in vitro than wild type bacteria; however, recovery of these mutants from mice was not affected by L. crispatus. We also found no evidence that utilization of lactobacillus-produced lactate by N. gonorrhoeae balances the detrimental effects of H2O2 during infection. We conclude the relationship between lactobacilli and gonococci is complex and may be subject to factors that have not been reproduced in vitro.