This chapter discusses the etiology, diagnosis and treatment of certain sexually transmitted diseases (STDs), including gonococcal (GC) infections, chlamydia infections, syphilis, genital herpes, pelvic inflammatory disease, HIV/AIDS, and hepatitis B. Gonorrhea is frequently asymptomatic in both men and women. Patients with gonococcal infections need to be evaluated for other sexually transmitted diseases, including chlamydia, HIV, hepatitis B and/or syphilis when appropriate. Neurosyphilis can occur, with symptoms of central nervous system (CNS) changes such as tabes dorsalis or dementia. All patients with syphilis should be tested for hepatitis B and HIV infections. Sex partners of women with pelvic inflammatory disease (PID) should be treated, especially to cover chlamydia and gonorrhea. Testing for HIV should be offered to all women, not just those whose behaviors may put them at risk of transmission, but to all women with an STD, including HPV.