Sexually transmitted diseases, despite vigorous efforts in prevention, are still existing and may provide portal of entry for human immunodeficiency virus transmission. Syphilis and gonococcal infection are decreasing but remain a problem in developing countries and their return cannot be excluded, despite active therapy. In industrial countries, viral infections are expanding. Herpes genitalis is the most common cause of genito-anal ulceration and anogenital warts have been steadily rising in the past decades. Some human papillomavirus genotypes are oncogenic. No treatment is able to eradicate them.