The diagnosis of GERD requires the thoughtful evaluation of a patient's symptoms and clinical course. In young patients with classical reflux symptoms in the absence of untoward complications such as structure, bleeding or pulmonary aspiration, antireflux treatment can be instituted without the need for diagnostic testing. A large number of patients will demonstrate a good clinical response to medical therapy. The diagnostic challenge arises when symptoms of reflux masquerade as cardiac and pulmonary disease or do not respond to simple medical treatment. The use of diagnostic testing to determine the presence and quantity of reflux is helpful in establishing the diagnosis in atypical settings. Prolonged pH monitoring offers the opportunity to monitor symptoms in a physiologic setting over a prolonged period and to provide a correlation of symptoms with the presence of reflux. Endoscopic evaluation is most important in evaluating patients with complications such as peptic strictures, hemorrhagic esophagitis, or Barrett's metaplasia. In these situations, important diagnostic and prognostic information as well as therapeutic intervention can be gained through endoscopy. In patients with peptic strictures, palliation can be achieved by endoscopic dilatation. The number of options available for the medical management of reflux disease has increased significantly in recent years. The introduction of effective agents to block acid secretion has provided a significant advance in the medical treatment of gastroesophageal reflux. Prokinetic agents offer an attractive alternative either alone or in combination with acid inhibition. Early results using parietal cell proton-pump blocking agents suggest that they may be effective in the treatment of severe esophagitis previously resistant to medical therapy. Despite significant advances in the medical treatment of GERD, a number of patients (5 to 10 per cent) may require antireflux surgery. The Nissen fundoplication has been shown to be an effective means of attaining mucosal healing usually accompanied by symptomatic relief. The use of a "loose wrap" performed over a large bore dilator avoids the postoperative problems of dysphagia or gas bloat. Despite improvements in our diagnostic and therapeutic armamentarium, a number of patients continue to pose a challenge for the clinician. There remains a clear need for more well-designed, well-controlled studies to assist in the effective treatment of this ubiquitous and often debilitating disease.