BACKGROUND Return to the operating room (ROR) has been put forth by the National Quality Forum and the American College of Surgeons as a surgical quality indicator. However, current quality metrics fail to consider the nature and etiology of the ROR. OBJECTIVE To provide a comprehensive description of all reoperations after neurosurgical procedures and assess the validity of ROR as a quality measure in neurosurgery. METHODS We retrospectively analyzed all neurosurgical procedures performed in a high-volume, tertiary care academic medical center between June 1, 2014 and December 31, 2016. Based on a system constructed and validated at our institution, we classified RORs into (a) unplanned related, (b) planned return due to complications, (c) planned-staged return, or (d) unrelated return. RESULTS A total of 9200 unique neurosurgical cases were identified, of which 788 had an ROR within 45 d (8.6%). Median time to ROR (interquartile range) was 9 d (4-15). Specifically, 4.2% were planned-staged returns, 3.4% were unplanned related, 0.3% were unrelated, and 0.6% were planned because of previous complications. Cranial procedures had the highest unplanned ROR rate (4.2%), followed by spinal (2.8%) and peripheral nerve (0.4%). The most common reason for an unplanned ROR was wound complication/surgical site infection (34.3%), followed by hematoma evacuation (13.9%) and cerebrospinal fluid (CSF) leak (11.3%). CONCLUSION Unplanned RORs were relatively rare and most commonly associated with wound complication, postoperative hematoma, and CSF leak. To better reflect surgical quality, ROR metrics should indicate whether the return was planned or unrelated.