The following pages summarize the proceedings of a symposium held in May 2006 on the emerging role of on-demand therapy for gastroesophageal reflux disease (GERD). Medical therapy for GERD has undergone significant change in recent years with the advent of effective, but expensive, antisecretory agents. On-demand (patient-driven) therapy is attractive to payers and patients, because it appears to be both cost-effective and convenient. Many individuals appear to accept occasional symptomatic breakthrough in exchange for personal control of their disease. On-demand therapy should be distinguished from intermittent therapy, which is either patient- or physician-driven, but which requires intermittent episodes of continuous therapy followed by discontinuation until symptoms recur. Proton pump inhibitors appear to be effective on-demand agents despite theoretical pharmacodynamic limitations for this class of drug. The available data support the use of on-demand therapy for GERD in uninvestigated reflux disease, nonerosive reflux disease, and possibly mild esophagitis as well. On-demand therapy should not be considered for patients with severe esophagitis.