Sexually transmitted infections (STIs) affect people of all ages and social groupings, and the personal and societal impact of these infections make them a major concern for public health. Federal, state, and local public health agencies monitor select STI outbreaks, and results are tracked and reported on a national level by the Centers for Disease Control (CDC). This chapter begins with a discussion of STIs in general, followed by specific sections covering HIV; STIs that cause cervicitis: chlamydia, gonorrhea, pelvic inflammatory disease (PID), and epididymitis; vaccine preventable STIs: human papillomavirus (HPV) and hepatitis B; ulcerative STIs: syphilis and herpes simplex virus (HSV); and finally those STIs that cause alterations in vaginal discharge: bacterial vaginosis (BV), trichomoniasis, and moniliasis. It includes the CDC guidelines for the treatment and management of STIs, such as pediculosis pubis, hepatitis A, chancroid, and lymphogranuloma venereum. The chapter covers teaching and self-care on STIs in general.