Total hip replacement (THR) has a very good clinical outcome. Peri-prosthetic infection is a severe complication with infection rates 0.5-2% after primary THR. Systematic reviews and meta-analyses published in recent years have allowed drafting of evidence based guidelines for diagnosis and treatment of peri-prosthetic infection after THR. If an implant related infection is suspected, a complex standardised procedure should be carried out. The most commonly cultured microorganisms causing peri-prosthetic infections are coagulase-negative staphylococci and S.aureus followed by mixed flora, streptococci, gram-negative bacilli, enterococci and anaerobes. Different treatment strategies can be applied regarding virulence of a specific pathogen, mechanical stability of the implant and patient's condition. Treatment options always include antibiotic therapy with/without surgical procedures like debridement, one/two stage approach or resection arthroplasty.