Aspirin and P2Y12 receptor antagonists are widely used across the spectrum of cardiovascular and cerebrovascular diseases. Gastrointestinal complications, including ulcer and bleeding, are relatively common during antiplatelet treatment and, therefore, concomitant proton pump inhibitor (PPI) treatment is often prescribed. However, potential increased risk of cardiovascular events has been suggested for PPIs, and, in recent years, it has been discussed whether these drugs may reduce the cardiovascular protection by aspirin and, even more so, clopidogrel.