Background: The number of spinal surgeries performed worldwide have significantly increased over the past decade. However, to the best of our knowledge, there are no national or international studies that report the overall picture of complications following spinal surgery. This article sought to identify the incidence and causes of reoperations in patients undergoing spinal surgery, as well as the average time from index surgery to reoperation. Furthermore, the purpose was to identify the microbiological agents present in cultures from infected patients.Methods: This was a retrospective cohort study that used a university hospital's medical records as the data source. The study population comprised 2110 patients who underwent spinal surgery during a 40-month period between 2015 and 2018. All suspected reoperations were verified manually. Additional data collected for reoperations included cause, time from index surgery, and laboratory results from cultures. Descriptive analysis was used.Results: The incidence of reoperations during the study period was 11% (n = 232). The most common cause of reoperation was infection (28%, n = 65), followed by implant-related causes (19%, n = 44) and hemorrhage/hematoma (15%, n = 34). The time between index surgery and reoperation varied, but half of all reoperations occurred within 30 days. Coagulase-negative staphylococci were the most common type of bacteria (positive cultures in 39% of infected patients). Conclusion:The number of reoperations in the studied hospital were high during the study period. Infections accounted for a large percentage of reoperations, suggesting that effective preventive measures might significantly reduce the total number of reoperations.Clinical Relevance: Postoperative infection causing reoperations after spinal surgeries is a large problem, and finding effective preventive measures should be a priority for caregivers.Level of Evidence: 3.