Sexually transmitted diseases (STDs) can substantially increase the morbidity and mortality of exposed adults and children. Despite the advent of new antibiotics and focus on behavioral interventions such as condom use, attempts to limit the spread of STDs have been largely unsuccessful. Vaccines have received increasing attention as a potential strategy for STD control. This article focuses on the current status of vaccine research for five classic STDs: gonorrhea, genital herpes, syphilis, chancroid, and chlamydia.