Periprosthetic infection remains a major complication in arthroplasty; increasing numbers of primary and revision arthroplasties are being followed by increasing numbers of periprosthetic infections. In cases of possible infection, the surgeon must have a treatment concept that can be individually adjusted. Diagnosis is a challenge and should include a variety of investigations. In early and secondary infections, component retention can be successful. Surgical debridement is the key to success. All late and chronic infections should be treated by explantation of all components because of infection with biofilm-producing microbes. The individual patient's situation and the surgeon's experience should determine whether to choose direct single-stage or two-stage revision. New diagnostic and therapeutic procedures can improve outcomes but cannot replace the need for prophylactic efforts.