Immunoglobulin G (IgG) subclass deficiency is a rare primary immunodeficiency syndrome characterized by recurrent infections and autoimmune disorders. However, there have been no reports of ocular involvement, either inflammatory or infectious, in association with IgG subclass deficiency. The authors report the first case of retinal vasculitis that led to the diagnosis of IgG subclass deficiency, in a patient with a history of inflammatory bowel disease and recurrent infections of previously unknown origin.