Abstract INTRODUCTION Unplanned hospital readmission after discharge is an important quality metric. Such readmissions are associated with greater healthcare costs, decreased patient satisfaction, decreased clinical outcomes, and sometimes financial penalties. A large amount of data has been documented regarding 30-d readmissions for neurosurgical populations. However, a focus on 7-d readmissions may provide an insight into the causes of unplanned readmissions, perhaps translate into decreases in 30-d readmissions. This study was performed in order to determine the causes of 7-d readmissions and to define risk factors that, if addressed, would allow for a reduction of such readmissions. METHODS All patients readmitted after discharge within 7 d from the neurosurgical service from the University of Pittsburgh Medical Center, Presbyterian Hospital, during 2018 were evaluated. There were 18 different providers. Demographic data were collected for all patients. The primary reason for readmission was organized using a 5-category system: surgical site infection, pain, altered mental status/seizures, other postoperative complications [eg, venous thromboembolism (VTE), urinary tract infection, pneumonia, CSF leak, hematoma, shunt failure] and “unrelated.” RESULTS Of 5184 discharges, 169 patients (3.3%) were readmitted within 7 d (55% men; mean age 62 yr). A total of 65% had undergone care for cranial pathology and 35% for spine (versus 55% and 45%, respectively, in the total discharge population). Other postoperative complications were the leading cause of readmission (40%), followed by altered mental status/seizure and unrelated (20% each). Surgical site infection and postoperative pain exhibited the lowest rates of 10% each. CONCLUSION The overall 7-d readmission rate was 3.3%. There was nearly a 2:1 ratio for cranial versus spinal patients for 7-d readmissions. The majority of readmissions were related to postoperative complications, whether directly related to surgical intervention or perioperative complications. Focal efforts to decrease specific postoperative complications should translate into a reduction in both 7- and 30-d unplanned readmissions.