In the neonatal foal septic arthritis is an important cause of morbidity that may limit future athletic performance. This is often despite a good prognosis for resolution of joint infection. This article presents a review of the diagnosis and treatment of septic arthritis in foals less than 2 months of age, including an overview of our current understanding of inflammatory joint disease in the neonate. Management options are described, with emphasis on tailoring therapy to the individual foal based on accurate staging and monitoring of the disease process. Special considerations relevant to the immature animal are addressed.