This article explains a prospective study at an academic hospital studying adverse events in 400 consecutive patients after discharge from a medical service. The authors describe the incidence, severity, and preventability of reported events along with specific examples captured during the study. They discuss strategies to improve patient safety by emphasizing the vulnerability of the discharge transition from hospital to home. The study identifies an important target for future interventions by suggesting improvement in the coordination and follow-up of care immediately after hospital discharge.