This consensus document sets out proposals for antibiotic prophylaxis in abdominal, urological, gynaecological, orthopaedic, vascular and thoracic surgery. As far as possible the recommendations are based on prospective controlled trials. However, for some procedures, e.g. lung surgery and implantation of pacemakers, documentation is lacking but antibiotic prophylaxis is given traditionally. The choice of antibiotics is generally conservative, emphasizing that antibiotics used for therapy should be avoided in prophylactic regimens. Most recommendations are for the use of a first- or second-generation cephalosporin or an isoxazolyl penicillin, when necessary, combined with a nitroimidazole derivative (metronidazole or tinidazole). Suggestions are given for more frequent use of orally administered antibiotics, such as co-trimoxazole, doxycycline, metronidazole or tinidazole. Emphasis is put on short-term prophylaxis. In most cases surgical antibiotic prophylaxis should be given as a single dose and in no case should the prophylaxis time exceed 24 h.