The purpose of this study was to develop an aneurysm model that mimics the tortuous anatomy of the cerebrovasculature for the evaluation of endovascular devices. This model is an adaptation of the carotid siphon model of Georganos et al. The common carotid artery trunks in 10 swine were surgically elongated using an EXXCEL Soft ePTFE vascular graft and then sutured into position to form an S-curve, with each bend having a 5- to 10-mm radius. Following a 3- to 4-week healing period, aneurysms were surgically created from jugular vein grafts along or distal to the tortuous segment and immediately embolized with coils. In a subset (n = 6) of the arteries, a stent was also placed across the aneurysm neck. Animals were allowed to survive for 30 days. Clinical relevance and utility of the model were evaluated based on comparison to human angiographic images, physician feedback, and histopathological assessment. Tortuous anatomy was successfully created in all 10 animals, and aneurysms were added at various locations within or distal to the tortuous segment in a subset of 8 animals, creating 11 aneurysms in total. At 30 days, 18/20 vessels were patent and the bend radius was maintained. Endovascular access to aneurysms and placement of embolization coils and/or stents was successful in 10 of 11 attempts. Physician feedback indicated this tortuous model was more clinically relevant in terms of endovascular device delivery and deployment compared to established, nontortuous aneurysm models.