All patients are not equally at risk when it comes to postoperative infections, whether the risks are related to the environment or the patient. Patient-specific infection risk factors for arthroplasty should be a focal point during the preoperative consultation as they impact the treatment decision. Eighty percent of patients have at least one modifiable infection risk factor. These risk factors must be corrected preoperatively whenever possible so that the patient is operated under the best possible conditions, with the lowest possible infection risk. The screenings and preoperative preparations are multidisciplinary but must also involve the patient. The information provided to the patient must match the patient's infectious risk profile. This lecture will review every infection risk factor, whether it is modifiable or not, and then suggest how the treatment decision should be adapted to each patient's infection risk.