X-linked agammaglobulinemia (XLA) has been associated with a broad range of infections, but enteroviral disease represents one of the most damaging infections. The risk of enteroviral infection in XLA is lower now than in the setting of intramuscular immunoglobulin or in patients without immunoglobulin replacement, but the rate of infection has not declined significantly in the era of intravenous immunoglobulin replacement. Enteroviruses can cause inflammation of nearly every organ, but in XLA, infections often manifest as dermatomyositis or chronic meningoencephalitis. Difficulty and delay in recognizing symptoms and lack of specific therapy contribute to the poor outcomes. Furthermore, cerebrospinal fluid detection of enteroviruses is not very sensitive. Reluctance to perform brain biopsies can lead to significant delays. The other feature compromising outcomes is the lack of specific therapy. High-dose peripheral and intraventricular immunoglobulin have been used, but failure is still common. New antienteroviral drugs are in development and show promise for immunodeficient patients with life-threatening infections with enterovirus. (C) 2016 American Academy of Allergy, Asthma & Immunology.