OBJECTIVE Large interhemispheric subdural hematomas (iSDHs) causing falx syndrome are rare; therefore, a paucity of data exists regarding the outcomes of contemporary management of iSDH. There is a general consensus among neurosurgeons that large iSDHs with neurological deficits represent a particular treatment challenge with generally poor outcomes. Thus, radiological and clinical outcomes of surgical and nonsurgical management for iSDH bear further study, which is the aim of this report. METHODS A prospectively collected, single-institution trauma database was searched for patients with isolated traumatic iSDH causing falx syndrome in the period from January 2008 to January 2018. Information on demographic and radiological characteristics, serial neurological examinations, clinical and radiological outcomes, and posttreatment complications was collected and tallied. The authors subsequently dichotomized patients by management strategy to evaluate clinical outcome and 30-day survival. RESULTS Twenty-five patients (0.4% of those with intracranial injuries, 0.05% of those with trauma) with iSDH and falx syndrome represented the study cohort. The average age was 73.4 years, and most patients (23 [92%] of 25) were taking anticoagulants or antiplatelet medications. Six patients were managed nonoperatively, and 19 patients underwent craniotomy for iSDH evacuation; of the latter patients, 17 (89.5%) had improvement in or resolution of motor deficits postoperatively. There were no instances of venous infarction, reaccumulation, or infection after evacuation. In total, 9 (36%) of the 25 patients died within 30 days, including 6 (32%) of the 19 who had undergone craniotomy and 3 (50%) of the 6 who had been managed nonoperatively. Patients who died within 30 days were significantly more likely to experience in-hospital neurological deterioration prior to surgery (83% vs 15%, p = 0.0095) and to be comatose prior to surgery (100% vs 23%, p = 0.0031). The median modified Rankin Scale score of surgical patients who survived hospitalization (13 patients) was 1 at a mean follow-up of 22.1 months. CONCLUSIONS iSDHs associated with falx syndrome can be evacuated safely and effectively, and prompt surgical evacuation prior to neurological deterioration can improve outcomes. In this study, craniotomy for iSDH evacuation proved to be a low-risk strategy that was associated with generally good outcomes, though appropriately selected patients may fare well without evacuation.