The goal of this study was to evaluate the feasibility of endoscopic transtympanic balloon dilation of the cartilaginous eustachian tube. To accomplish this, transtympanic balloon dilation of the cartilaginous eustachian tube was performed on 11 eustachian tubes (6 cadaver heads). The balloon catheter was introduced and passed through the protympanic orifice of the eustachian tube transtympanically under endoscopic view and cannulated without incident in all cadavers. Computed tomography was then performed postprocedure to evaluate for inadvertent dilation of the bony eustachian tube, adverse placement of the balloon, or any bony fractures. The balloon was seen to be successfully inflated in the cartilaginous portion without damage to surrounding structures in all cases. This demonstrates that under endoscopic guidance, the protympanic orifice of the eustachian tube can be feasibly cannulated and reliably traversed, allowing for targeted dilation of the cartilaginous eustachian tube from a transtympanic approach.