OBJECTIVE : To evaluate clinical and imaging features before embolization, data of embolization procedure and outcome in patients with ruptured or unruptured intracranial arteriovenous malformation (AVM) who were treated by endovascular embolization using detachable-tip microcatheters and Onyx 18®. METHODS : Forty-three patients treated with endovascular embolization using a detachable-tip microcatheter and Onyx18® between January 2008 and April 2016 were evaluated. There were 27 men and 16 women with a mean age of 35.9±14.1years (range: 10-68years). Clinical and imaging features, embolization details and post-treatment findings were analyzed. Patients were divided into ruptured AVM and unruptured AVM groups. Death, complications and total embolization rates of each group were assessed. RESULTS : Fifty-one embolization sessions were performed in 43 patients. Total embolization rate was 40% (17/43). There were significant relationships between AVM diameter and total embolization success and AVM diameter and complication rates. The degree of embolization was partial in all patients who had complications. Catheter retention and iatrogenic rupture were not observed in any procedure. No major neurologic deficit was seen in patients who had unruptured AVM and complications after treatment. CONCLUSIONS : Our results show the efficacy of endovascular embolization of AVM using detachable-tip microcatheters and Onyx 18®. A new AVM classification system based on AVM diameter for this embolization technique may be more predictive in terms of total embolization success and complication development.