Background In the past 5 years, new treatment materials and techniques offering a different concept inendovascular treatment have been described for cerebral arteriovenous malformations (CAVMs)·The aim of thisstudy was to assess the endovascular treatment of CAVMs by using a liquid embolic material, Onyx (MicroTherapeutics·Inc·, Irvine, CA, USA)·Methods From September 2003 to September 2004, Onyx was used to treat 22 patients with CAVMs·TenAVMS were located in functional areas, 8 in deep cerebral areas, and 4 in the cerebellar hemisphere·The sizeof CAVMs was about3 cm in diameter in 5 patients, 3 -6 cm in 11, and more than 6 cm in 6·Results In the 22 patients, Onyxembolization was successful·Nidus occlusion was complete in3 patients, >90% in 8, >80% and <90% in 6, and >50% and <80% in 5·Complications included transientneurological deficits in 2 patients, and adherence of microcatheter to the site of injection in 2·Conclusions Being non-adhesiveness, Onyx is a safe and satisfactory embolic material in the treatment ofCAVMs·But its long-term efficacy awaits further follow-up· Background In the past 5 years, new treatment materials and techniques offering a different concept of inendovascular treatment have been described for cerebral arteriovenous malformations (CAVMs) · The aim of this study was to assess the endovascular treatment of CAVMs by using a liquid embolic material, Onyx ( MicroTherapeutics Inc., Irvine, CA, USA) • Methods From September 2003 to September 2004, Onyx was used to treat 22 patients with CAVMs • TenAVMS were located in functional areas, 8 in deep cerebral areas, and 4 in the cerebellar hemisphere • The size of CAVMs was about 3 cm in diameter in 5 patients, 3 -6 cm in 11, and more than 6 cm in 6. Results In the 22 patients, Onyxembolization was complete · Nidus occlusion was complete in 3 patients,> 90% in 8, > 80% and <90% in 6, and> 50% and <80% in 5 * Complications included transient neural deficits in 2 patients, and adherence of microcatheter to the site of injection in 2 · Conclusions Being non-adhesiveness, Onyx is a safe and satisfa ctory embolic material in the treatment ofCAVMs · But its long-term efficacy awaits further follow-up ·