Big data has been with us for a long time, and tools to explore it continue to improve. Where are these data resources, how are we using them, and what are we finding as we explore them? Laboratory information systems accumulate billions of results, healthcare organizations collapse them into billions of charges for laboratory services, and healthcare management databases aggregate laboratory activity into millions of items related to labor and other expense of operating laboratories. These sources feed into gaining insight into provider ordering practices, patient safety outcomes, and operational efficiencies. Examples include CMS reimbursement incentives and Choosing Wisely campaigns to reduce waste in provider practices, both of which incorporate laboratory data in their measures. While there are almost infinite opportunities to advance patient safety and organizational efficiency, there are also risks associated with availability, use, and interpretation of big data. These and other topics will be explored in this presentation.