Spontaneous bilateral carotid and vertebral artery dissections (CADs and VADs) are rare. A 29-year-old female presented with a collapse, 4 weeks after a sudden onset of severe neck and shoulder pain. CT scan revealed diffuse subarachnoid hemorrhage (SAH) and early hydrocephalus. Angiography revealed bilateral CADs and VADs, along with multiple fusiform and saccular aneurysms. Systemic vessels - including the renal arteries - were normal, and no risk factors or underlying vasculopathy were apparent. The presumed source of SAH (a posterior cerebral artery aneurysm) was successfully clipped. Each dissection, by contrast, was managed conservatively with heparin prophylaxis; and spontaneous CAD and VAD resolution occurred within 6 months. We present a unique case of four-vessel dissection associated with multiple disparate saccular and fusiform aneurysms. We suspect that underlying vasculopathy - perhaps novel - may become apparent with time.