OBJECTIVE: Intraoperative aneurysm rupture (IPR) always results in a poor prognosis for the patient. However, the risk factors of IPR are unclear. In this article, the risk factors are explored, a nomogram model for predicting IPR is established, and the prognostic factors for patients with IPR are analyzed. METHODS: A total of 549 patients with aneurysm, which were embolized from September 2011 to September 2015, were enrolled for analysis. Univariate and multivariate logistic regression were performed to explore the risk factors for IPR, and a nomogram was established. A nonparametric Mann-Whitney U test was performed to analyze prognostic factors for patients with IPR. RESULTS: Twenty-one patients (4.4%) experienced IPR. In univariate analysis, Hunt-Hess grade (P = 0.002), time from hospitalization to treatment (P = 0.08) and subarachnoid hemorrhage (SAH) to treatment (P = 0.08), aneurysm neck (P = 0.08), assistive technique (P = 0.03), and intraoperative cerebral vasospasm (P < 0.001) were significantly associated with IPR. In multivariate analysis, Hunt-Hess grade (odds ratio [OR], 8.177; 95% confidence interval [CI], 1.714-39.012; P = 0.008), aneurysm neck (OR, 5.629; 95% CI, 1.149-27.575; P = 0.033), assistive technique (OR, 1.393; 95% CI, 0.961-2.018; P = 0.080), and intraoperative cerebral vasospasm (OR, 4.280; 95% CI, 1.081-16.947; P = 0.038) were independent risk factors for IPR. Hydrocephalus (P = 0.069), history of SAH (P = 0.10), >= 2 SAH (P = 0.051), location of aneurysm (P = 0.09), and number of aneurysms (P = 0.025) were associated with the bad outcome. CONCLUSIONS: Hunt-Hess grading, aneurysm neck, intraoperative assistive technology, and vasospasm were independent risk factors for IPR. Hydrocephalus requiring surgical intervention, times of rupture, location of aneurysm, and the number of aneurysms were relevant to the prognosis of patients.