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BACKGROUND Relative risk is insufficient to guide treatment decision making for unruptured intracranial aneurysms. OBJECTIVE To introduce a novel risk assessment methodology called Rupture Criticality Index (RCI), which allows for concurrent evaluation of groups of risk factors (RFs). METHODS From a retrospective database of saccular aneurysms, we identify 915 patients and delineate 50 potential RFs for aneurysms in 11 unique locations. RF combinations for multivariable analysis were defined by aneurysm size, location, and a third variable from the study design. Data analysis was performed by applying frequency distribution methods to define the RCI of each RF combination. RESULTS RF combinations at greatest risk were small (4.8-8.2 mm) or medium (8.3-14.5 mm) anterior communicating aneurysms (ACoA) in males (RCI 9.87-10), small ACoA in ≤37 years or 38-55 years (RCI 8.67-8.99), medium basilar tip aneurysms (BTA) in males (RCI 10), and large (14.6-22.5 mm) BTA in Caucasians or 38-55 years (RCI 9.25 & 9.35). CONCLUSION We introduce the concept of RCI and compare how RF combinations are associated with aneurysmal rupture. This novel approach to aneurysmal rupture identifies high-risk clinical presentations and can be used to guide clinical decision making in patients with non-traditional risks.