SummaryIn no other medical field former rare infections of the 1980th and 1990th occur again as this is seen in the field of venerology which is as well based on the mobility of the population. Increasing rates of infections in Europe, and increasing bacteriological resistances face health professionals with new challenges. The WHO estimates more than 340 million cases of illnesses worldwide every year. Diseases caused by sexually transmitted infections (STI) in a strict sense are syphilis, gonorrhea, lymphogranuloma venereum, granuloma inguinale, and chancroid. In a wider sense, all illnesses are included which can mainly be transmitted through sexual contact. The term “sexual contact” has to be seen widely, from close physical contact to all variants of sexual behavior. This CME article is an overview of the most common occurring sexually transmitted infections in clinical practice. Both, basic knowledge as well as recent developments are discussed below.