This study evaluated patients' preoperative platelet function and the relation between acute embolic or hemorrhagic complications in unruptured intracranial aneurysm patients undergoing stent treatment. From September 2013 to December 2013 we prospectively collected clinical data in all unruptured intracranial aneurysm patients undergoing stent-assisted coiling. All patients received a dual antiplatelet therapy (aspirin and clopidogrel) protocol. Diffusion-weighted 3-T MRI was performed for cerebral aneurysm patients within 24 hours after treatment. Platelet function was tested by thromboelastography. Forty-six patients with 50 intracranial aneurysms treated by stent-assisted coiling were included. Fifty-three stents were deployed in 46 procedures, including 39 Enterprise stents and 14 Solitaire stents. Acute ischemia was detected in the territory of the stented vessel in 25 of 46 patients (54.3%), but did not cause permanent disability. There was a significant difference between groups with and without thromboembolism in terms of percentage platelet inhibition and ADP-induced clot strength (MA(ADP)) for clopidogrel, but no significant difference with aspirin. MA(ADP) had a predictive value yielding an area under the ROC curve of 0.67 (95% CI: 0.57-0.81, P < 0.05). Anterior circulation aneurysms were also associated with ischemic events (P = 0.034). Silent acute embolism may be frequent in unruptured intracranial aneurysm treated with stent-assisted coiling even when dual antiplatelet therapy is given. The antiplatelet inhibition parameter (MA(ADP)) was a predictor for acute thromboembolism in unruptured intracranial aneurysm patients treated by stent-assisted coiling.