Object. The purpose of this study was to report the authors' experiences in stent-assisted coil embolization (SAC) of ruptured wide-necked aneurysms in the acute period and to evaluate the incidence of and risk factors for periprocedural complications.Methods. A total of 72 patients were recruited for this study between March 2007 and June 2012. All patients met the following criteria: 1) the presence of ruptured intracranial wide-necked saccular aneurysms, and 2) the patient underwent SAC for treatment of those aneurysms within 72 hours of rupture. All of the patients with clinically poor grades or acute hydrocephalus underwent external ventricular drainage (EVD) before SAC. The incidence of and risk factors for periprocedural complications were retrospectively evaluated.Results. Of the 72 patients included in this study, periprocedural complications occurred in 14 (19.4%), including asymptomatic complications in 4 (5.6%) and symptomatic complications in 10 (13.9%); there were symptomatic thromboembolic complications in 5 patients (6.9%), and symptomatic hemorrhagic complications in 5 (6.9%). The authors observed no subacute or delayed thromboembolic complications during the follow-up period of 18.8 months. Use of EVD (OR 1.413, 95% CI 0.088 -2.173; p = 0.046) was the only independent risk factor for periprocedural complications on multivariate logistic regression analysis.Conclusions. The periprocedural complication rate during SAC was 19.4% among 72 patients. Because of the high complication rate, microsurgical clipping or endovascular treatment with another technique (multiple-microcatheter or balloon-assisted technique) may be a more appropriate option for first-line treatment than SAC, especially in patients requiring EVD. (http://thejns.org/doi/abs/10.3171/2014.4.JNS131662) keY WorDS • periprocedural complication • ruptured intracranial aneurysm • stent-assisted coil embolization • wide-necked aneurysm • vascular disorders Abbreviations used in this paper: ACT = activated clotting time; EVD = external ventricular drainage; GOS = Glasgow Outcome Scale; GP = glycoprotein; IPH = intraparenchymal hemorrhage; SAC = stent-assisted coil embolization; SAH = subarachnoid hemorrhage.