Since their introduction in the late 1980s, proton pump inhibitors (PPI) have demonstrated gastric acid suppression superior to that of histamine H2-receptor blockers. This class of drugs has improved the treatment of various acid-peptic disorders, including gastroesophageal reflux disease, peptic ulcer disease, and nonsteroidal anti-inflammatory drug-induced gastropathy. PPIs have minimal side effects and few significant drug interactions. They are generally considered safe for long-term treatment. We present a rare side effect, acute pancreatitis, occurring in a patient who was treated with the proton pump inhibitor omeprazole.