Sexually transmitted diseases (STD) cause lower genital tract infections (cervicitis, vaginitis) or ascending infections of the fallopian tubes, and, possibly, pelvic inflammatory disease (PID). The syphilis bacterium, human immunodeficiency virus (HIV), and the hepatitis virus cause systematic disease. Although oral contraceptives (OCs) are the most reliable contraceptive method, they have limited anti-STD properties and their relationship with STDs remain unclear. Various mechanisms explain a protective role of OCs against STDs; however, in no way can OCs be considered a safe anti-STD contraceptive method, when compared to specific barrier methods, which provide both contraception and anti-STD protection. The above has been confirmed by a recent study performed in our institution where 10.3% and 6.9% of OC users presented a prevalence of Chlamydia trachomatis and Mycoplasma, respectively, when compared to 0% and 4.5% infection rates found among condom users. It is concluded that although OCs possess some anti-STD properties, mainly in the prevention of PID, they should be used in combination with a barrier method.