Brucella infection in arthroplasties is a rare event. An unspecific clinical symptomatology is associated with unclear radiographic peri-prosthetic signs of bone halisteresis. Only a positive anamnesis, combined with an antibiogram of the joint liquid and a high serum antibody titre, can lead to a definitive diagnosis. We report a case of Brucella melitensis infection in a total knee arthroplasty implanted 2 years earlier. With the absence of radiological signs of prosthetic loosening and thanks to a systemic antibiotic combined therapy (rifampicin + doxycycline) extended for 8 weeks, we were able to solve the infection avoiding surgery.