Objective: Hydrocephalus is a frequent complication of subarachnoid hemorrhage (SAH) following the rupture of intracranial aneurysms. Chronic hydrocephalus develops in 6 to 40% of patients and may require insertion of a ventriculo-peritoneal drain (VPS). The objective of the study is to identify the independent predictor and establish a predictive model of shunt dependency. Methods: 324 patients with HSA were recruited prospectively and consecutively as part of the @neuriST study. The analysis included eleven variables. A predictive model for shunt dependence was developed based on a multivariate analysis of the variables selected by the univariate analysis. The performance of the models was measured and compared to the CHESS score. Results: Shunt-dependent hydrocephalus developed in 38 (11.7%) patients. Ventricular hemorrhage, WFNS scale, Fisher grade, initial size of the third ventricle, posterior location of the aneurysm and placement of the external ventricular drain (EVD) have been associated with shunt-dependent hydrocephalus . The placement of an EVD and the posterior location of the aneurysm were independent predictors on the multivariate analysis. Classifiers based on the CHESS score, EVD placement alone or in combination with the location of the aneurysm showed similar performance. Conclusions: The initial placement of an external ventricular drain appears to be the best predictor of shunt dependence. Models with 1,2 or 5 variables (CHESS score) have similar predictive performance.