The modern therapy for peptic ulcer disease and other acid peptic diseases is based on administration of proton pump inhibitors (PPI) which have fully replaced anacids, parasympatholytics and histamine H2 receptor antagonists. The most effective way is to administer proton pump inhibitors in the morning on an empty stomach in a single daily dose. It is a very safe therapy, despite the fact that a potential adverse effect of long-term PPI treatment on the efficacy of other medications (clopidogrel), on bone metabolism and development of respiratory infections have been discussed recently. PPI also play an essential role in the eradication treatment of Helicobacter pylori infection, the prevention and treatment of gastropathy induced by nonsteroidal anti-inflammatory drugs and in relation to some rare hypersecretory conditions. The role of proton pump inhibitors in the therapy for functional dyspepsia is contradictory. Massive bleeding from the peptic ulcer is a relatively frequent complication of NSAID gastropathy. Endoscopic hemostasis and parenteral administration of PPI for at least 72 hours are used in therapy. Key words: acid peptic diseases - gastric secretion - peptic ulcer - proton pump inhibitors.