Arteriovenous malformations (AVMs) are complex vascular lesions for which transcatheter embolization is considered as the first-choice treatment. Onyx and N-butyl cyanoacrylate are two of the multiple off-label liquid embolizing agents. Their safety has been proved originally in neurointerventional radiology and also in peripheral radiology for embolizations. These liquid agents have many similarities as well as differences. This chapter presents modified Onyx technique tips and tricks in addition to the review of the literature of these two competitive embolic liquid agents. Their advantages, disadvantages over each other, indications, limitations, complications, and trouble shootings are briefly discussed.