An available supply of intravenous immunoglobulin (IVIG) is essential for individuals with primary humoral immunodeficiency. A shortage in 1997 prompted the Food and Drug Administration (FDA) to revise guidelines for the licensure, production, and distribution of new IVIG products, including the standardization of United States clinical trials regarding endpoints for safety, efficacy, and pharmacokinetics. The following review is intended to present current information and results of clinical trials in patients with primary immunodeficiency treated with IVIG products currently licensed or awaiting licensure in the United States. The data presented are compiled from published clinical trials and prescribing information generated by manufacturers. © Springer-Verlag 2012.