BACKGROUND: Innovation is a part of the daily practice of neurosurgery. However, a clear definition of what constitutes innovation is lacking and opinions vary from continent to continent, from hospital to hospital, and from surgeon to surgeon. METHODS: In this study, we distributed an online survey to neurosurgeons from multiple countries to investigate what neurosurgeons consider innovative, by gathering opinions on several hypothetical cases. The anonymous survey consisted of 52 questions and took approximately 10 minutes to complete. RESULTS: A total of 355 neurosurgeons across all continents excluding Antarctica completed the survey. Neurosurgeons achieved consensus (>75%) in considering specific cases to be innovative, including laser resection of meningioma, focused ultrasonography for tumor, oncolytic virus, deep brain stimulation for addiction, and photodynamic therapy for tumor. Although the new dura substitute case was not considered innovative, there was consensus among neurosurgeons indicating that institutional review board approval was still necessary to maintain ethical standards. Furthermore, although 90% of neurosurgeons considered an oncolytic virus for glioblastoma multiforme to be innovative, only 78% believed that institutional review board approval was necessary before treatment. CONCLUSIONS: Our results indicate that innovation is a heterogeneous concept among neurosurgeons that necessitates standardization to ensure appropriate patient safety without stifling progress. We discuss both the ethical drawbacks of not having a clear definition of innovation and the challenges in achieving a unified understanding of innovation in neurosurgery and offer suggestions for uniting the field.