Asthma and gastroesophageal reflux (GER) frequently coexist in patients. GER is usually considered to be potential trigger for asthma symptoms. This hypothesis is based more on pathophysiological considerations than on clinical data. Indeed, experimental data show that acid perfusion of the lower esophagus in humans induces increased bronchial hyperreactivity, and various mechanisms have been proposed to explain this observation. Recent studies also demonstrate that, in patients with asthma, obstruction induced by non-specific bronchial challenge increases the number of reflux episodes. This suggests that asthma by itself might be responsible for GER. Despite these facts, a review of published reports claiming to demonstrate the clinical effectiveness of medical or surgical treatment of GER on asthma symptoms yields inconsistent results. Nevertheless, it appears that a few asthmatic patients do benefit clinically and/or have improved lung function when treated for GER. However, the criteria for patient selection and, especially, the anti-reflux treatment modalities (choice and dose of medication and the duration of treatment) need to be more clearly defined through additional studies. (C) 2003 Elsevier SAS. Tons droits reserves.