OBJECTIVE Cerebral ischemia is a major contributor to poor outcome after ruptured anterior communicating artery aneurysms (ACoAs), and is not well classified. In this article, we develop a classification and identify risk factors of cerebral ischemia after ruptured ACoAs. METHODS Three hundred sixty patients with ruptured ACoAs undergoing microsurgical clipping were collected. Sex, age, smoking status, Hunt-Hess grade, Fisher grade, hospital stay, surgical timing, hypertension, diabetes, postoperative cerebral ischemia, and postoperative modified Rankin Scale score were collected. Postoperative ischemic changes are classified according to a novel grade (ischemic grade I-IV). RESULTS Predictive factors of postoperative ischemia (grade I-IV) included sex (odds ratio [OR], 1.956; 95% confidence interval [CI], 1.262-3.032; P = 0.003) and Fisher grade (OR, 1.813; 95% CI, 1.144-2.871; P = 0.011). Male sex had a tendency to develop postoperative cerebral ischemia (61.3% in the ischemia group vs. 45.7% in the nonischemia group), while surgical timing did not. However, in patients with postoperative ischemia, early surgery within 3 days (OR, 3.334; 95% CI, 1.411-7.879; P = 0.006) and advanced age greater than 55 years (OR, 2.783; 95% CI, 1.214-6.382; P = 0.016) were risk factors for postoperative neurologic deficits (grade III-IV). CONCLUSIONS Male sex and higher Fisher grade predict postoperative ischemia (grade I-IV), whereas surgical timing does not. However, in patients with postoperative cerebral ischemia, early surgery within 3 days and age greater than 55 years can increase the frequency of postoperative neurological deficits (grade III-IV). Older male patients undergoing early microsurgery had a tendency to develop neurologic deficits.