Infection of a peripheral joint following arthroscopic surgery is extremely rare, with an incidence of up to 0.42%. However, the consequences of delayed diagnosis can be dramatic. Besides taking an exact patient history, C-reactive protein determination and, especially, diagnostic arthrocentesis are required. For early-stage infections, arthroscopic therapy has been proven valuable. In addition, calculated and antibiogram-adjusted antibiotic therapy is essential. In the case of persisting signs of infection, re-arthroscopy should be considered quickly, with indications broad. The number of necessary revisions depends on the initial stage of infection. Postoperative immobilisation of the affected joint is occasionally essential for treating pain; otherwise, early mobilisation of the joint should be performed.