Taking inguinal hernia surgery as an example, the Swiss Medical Board has examined whether antibiotic prophylaxis is necessary in the event of what is known as a “clean” surgical procedure. According to the studies taken into account, infections after prophylaxis occur approximately half as frequently as without prophylaxis, although in patients without risk factors infection is very rare. Where antibiotics are used prophylactically across the board, it should be borne in mind that there is a risk of undesirable events such as severe allergic reactions, the development of resistance to antibiotics or the incorrect use of the medicine e.g. confusion. The Swiss Medical Board has therefore reached the conclusion that in patients without additional risk factors for the investigated surgery, pre-operative antibiotic prophylaxis is not necessary. Preoperative administration of antibiotics is recommended in patients with additional risk factors (such as age, inhibition of the immune system or serious accompanying illnesses).