For my thesis I performed a systematic review of the literature on equine synovial sepsis covering 1990-July 2021 using appropriate PICOS criteria. Of the 541 studies initially screened, 110 were retained in the final review. These were first reviewed from the perspective of the etiology of synovial sepsis, the frequency with which specific synovial structures were involved, and survival rates to discharge for foals and adults. Return to soundness and athletic performance were also analyzed for adults. The microorganisms most commonly identified and the prevalence of antimicrobial susceptibility were also reviewed. The most common cause of synovial sepsis in adults was trauma (70%) compared to hematogenous infection in foals (96%). Overall the most common form of synovial sepsis was septic arthritis, with the tarsus being the most affected joint in adults. The digital flexor tendon sheath and navicular bursa were the most commonly affected tendon sheath and bursa respectively. Survival rates to discharge (p=0.03) were higher in adults (83%) than foals (63%), but did not change over time (p=0.17). Rates of survival, return to soundness, and return to athletic performance did not differ for adults with septic arthritis, tenosynovitis, or bursitis. In adults the most common organisms isolated were Staphylococci, Streptococci, and E.coli, compared to E.coli, Rhodococcus equi, and Actinobacillus spp, in foals. Although antimicrobial data was limited, the prevalence of antimicrobial resistant coagulase-positive Staphylococci increased over the duration of the study. Prevalence of antimicrobial resistant coagulase-negative Staphylococci and beta-hemolytic Streptococci varied between antimicrobials.