A haematogenous infection of a joint prosthesis is rare, but the consequences can be very serious. For that reason, guidelines issued by medical professional organizations for antibiotic prophylaxis in treatments which involve risk have long existed. On the basis of experience in the United States and the Netherlands, it is clear that successive guidelines sometimes contradict each other and are often not appropriately applied in daily practice. This may be due to insufficient clarity concerning the most important patient risk factors. It remains, for example, unclear when there is a question of reduced immunity in the patient and when the oral region has to be considered to be infected. An appeal is made to follow the existing guidelines better, and, if possible, to achieve a more multidisciplinary revision of the guidelines 'Total hip prosthesis, so that they would be more widely adhered to.