Lyme prosthetic joint infection (PJI) is a rare event, but it is imperative to include Lyme disease as a possible cause of PJI in a Lyme-endemic region. The purpose of this article was to review the reported cases of Lyme PJIs in knee arthroplasty and to initiate the development of a treatment strategy. We found five cases of Lyme PJI in the literature. All patients lived in the northeastern region of the United States. Four patients were successfully treated with surgical intervention and postoperative antibiotics. One patient was successfully treated with intravenous and oral antibiotics for 6 weeks, without surgical intervention. Synovial fluid Lyme polymerase chain reaction and serological tests were positive in all patients. On follow-up visits, after completion of their treatment, all patients were asymptomatic with a painless functional knee. We recommend considering Lyme disease as a cause of culture-negative PJIs in endemic regions. Additional research is needed to clearly define a treatment algorithm. Based on our literature review, we cannot recommend a single best treatment modality for the treatment of Lyme PJI. However, early irrigation and de ´bridement with administration of postoperative antibiotics may improve early clinical outcomes. L yme arthritis is a common late manifestation of Lyme disease. It typically presents with joint pain associated with swelling and erythema. Clinically, it is very difficult to distinguish Lyme arthritis from a native septic joint. As far as we know, there have only been 5 cases of Lyme arthritis associated with total knee prosthetic joint infection (PJI) reported in the literature. [1][2][3][4] The management of PJI is based on the acuity of symptoms and can include irrigation and débridement, intravenous antibiotics, and implant retention if symptoms are of less than 3 weeks' duration. Chronic infection often requires a two-stage exchange arthroplasty and an extended course of antibiotics. 5 Diagnosis remains difficult and, when associated with Lyme disease, becomes very complicated. The Musculoskeletal Infection Society criteria are often used to assist in the diagnosis of PJI. 6 Timely diagnosis and early intervention decrease the morbidity and mortality associated with PJI. [5][6][7] If treatment is delayed, Lyme disease, caused by the spirochete Borrelia burgderfori, can lead Muzaffar Ali, DO