Communication failures at the time of patient handoffs have been frequently implicated in adverse events. While an extensive body of literature addresses handoff problems at shift changes, this systematic review investigates a less studied problem—adverse events arising from transferring patients between hospital units (e.g., from the emergency department to the inpatient floor). In addition to multiple studies documenting an alarming frequency of errors in such situations, this review identified several studies that successfully implemented interventions to reduce errors in intrahospital transfers. The review summarizes the key issues pertaining to safety in intrahospital transfers and suggests improvement strategies in each domain. An AHRQ WebM&M commentary discusses the tragic consequences of poor communication when a critically ill patient was transported from the inpatient ward to the radiology department.