We report the successful case of embolisation of a Barrow D (White et al. in Am J Neuroradiol 28:1415-1417, 2007) dural carotid cavernous fistula (CCF) with bilateral external carotid artery and internal carotid arterial supply, using a direct percutaneous transorbital approach with the embolic agent Onyx. In particular, we highlight the properties of Onyx which make it suitable to treat the multi-compartmental nature of CCFs. The patient developed transient complications which may be related to the volume of embolic agent used, and we discuss this point further. This is still a developing technique, and we present our case as a technical note to aid those contemplating embolisation via a transorbital approach with Onyx.