Purpose: Acute hydrocephalus is a common complication after aneurysmal subarachnoid hemorrhage (aSAH). It can be self-limiting or require cerebrospinal fluid diversion. We aimed to determine the transient acute hydrocephalus (TAH) rate in patients with aSAH treated endovascularly and evaluate its predictive factors. ----- Methods: A retrospective review of 357 patients with aSAH who underwent endovascular treatment from March 2013 to December 2019 was performed. Clinical and radiographic data were analyzed and risk factors with potential significance for acute hydrocephalus were identified. We constructed a new risk score, the Drainage Or Transiency of Acute Hydrocephalus after Aneurysmal SAH (DOTAHAS) score, that may differentiate patients who would experience TAH from those needing surgical interventions. ----- Results: Acute hydrocephalus occurred in 129 patients (36%), out of whom in 66 patients (51%) it was self-limiting while 63 patients (49%) required external ventricular drainage placement. As independent risk factors for acute hydrocephalus, we identified older age, poor initial clinical condition, aSAH from posterior circulation, and the extent of cisternal and intraventricular hemorrhage. The following three factors were shown to predict acute hydrocephalus transiency and therefore included in the DOTAHAS score, ranging from 0 to 7 points: Hunt and Hess grade ≥ 3 (1 point), modified Fisher grade 4 (2 points), and Ventricular Hijdra Sum Score (vHSS) ≥ 6 (4 points). Patients scoring ≥ 3 points had significantly higher risk for EVD (P < 0.0001) than other patients. ----- Conclusion: The newly developed DOTAHAS score can be useful in identifying patients with transient acute hydrocephalus. Further score evaluation is needed.