We conducted a meta-analysis to summarize rates of sexually transmitted infections among men who have sex with men (MSM) on pre-exposure prophylaxis (PrEP) for HIV versus MSM not using PrEP. Incidence rate ratios showed that MSM using PrEP were 25.3 times more likely to acquire a Neisseria gonorrhoeae infection, 11.2 times more likely to acquire a Chlamydia trachomatis infection, and 44.6 times more likely to acquire a syphilis infection versus MSM not using PrEP.