Antacids have for long been regarded as the mainstay of pharmacologic therapy in patients with dyspepsia. The advent of the histamine H2-antagonist and of proton pump inhibitors has provided simpler and overall more efficient therapeutic modalities for severe forms of dyspepsia. This relates especially to aggressive forms of peptic ulcer disease and severe reflux oesophagitis, where even high dose histamine H2-antagonist therapy has its clear limitations. Antacids nevertheless continue to be widely used in less severe forms of dyspepsia, especially in patients suffering from heartburn. In such patients self medication of antacids as first therapeutic measure is still very common. This is well exemplified by an American nd British survey. Out of 6760 randomly selected British general practice patients 875 suffered from reflux-like symptomatology without having consulted their physician for the symptomatology for minimum one year. Antacids were taken by 61% of them. The advent of controlled endoscopic trials and the emergence of the H2-receptor blockers as a yardstick of ulcer therapy, however, facilitated reappraisal of the value of antacids in various conditions. This has given a clear-cut answer in well defined entities such as peptic ulcer disease and stress ulcer prophylaxis but has left many open questions in heterogeneous conditions especially in and around gastroesophageal reflux disease.