Neurosurgery is a high-risk specialty currently undertaking the pursuit of systematic approaches to reducing risk and to measuring and improving outcomes. The authors performed a review of patterns and frequencies of adverse events in neurosurgery as background for future efforts directed at the improvement of quality and safety in neurosurgery. They found 6 categories of contributory factors in neurosurgical adverse events, categorizing the events as influenced by issues in surgical technique, perioperative medical management, use of and adherence to protocols, preoperative optimization, technology, and communication. There was a wide distribution of reported occurrence rates for many of the adverse events, in part due to the absence of definitive literature in this area and to the lack of standardized reporting systems. On the basis of their analysis, the authors identified 5 priority recommendations for improving outcomes for neurosurgical patients at a population level: 1) development and implementation of a national registry for outcome data and monitoring; 2) full integration of the WHO Surgical Safety Checklist into the operating room workflow, which improves fundamental aspects of surgical care such as adherence to antibiotic protocols and communication within surgical teams; and 3-5) activity by neurosurgical societies to drive increased standardization for the safety of specialized equipment used by neurosurgeons (3), more widespread regionalization and/or subspecialization (4), and establishment of data-driven guidelines and protocols (5). The fraction of adverse events that might be avoided if proposed strategies to improve practice and decrease variability are fully adopted remains to be determined. The authors hope that this consolidation of what is currently known and practiced in neurosurgery, the application of relevant advances in other fields, and attention to proposed strategies will serve as a basis for informed and concerted efforts to improve outcomes and patient safety in neurosurgery.