Renal arteriovenous malformations are rare, as is their embolization with Onyx. Endovascular curative embolization of renal arteriovenous malformations with Onyx is a relatively new procedure. Herein we present two cases of congenital and one case of acquired renal arteriovenous malformation embolized with Onyx 18 and their good results in the follow-up period. We used detachable microcatheters, which may be more advantageous than the nondetachable ones, during the superselective embolizations. Onyx, as an efficient embolic material, can be commonly used for curative embolization of the renal arteriovenous malformations.