IMPORTANCE: To demonstrate the usefulness of endovascular techniques in the treatment of fusiform, dissecting aneurysms. CLINICAL PRESENTATION: A 45-year-old woman presented with the acute onset of left-sided neck pain and headaches. Computed axial tomography demonstrated subarachnoid and intraventricular hemorrhage as well as a left posterior cerebellar infarct. Conventional cerebral and magnetic resonance angiography demonstrated a dissecting fusiform aneurysm at the origin of the left posteroinferior cerebellar artery. INTERVENTION: A balloon occlusion of the left vertebral artery at the posteroinferior cerebellar artery origin was tolerated without complication, and the patient underwent successful occlusion of the left posteroinferior cerebellar artery, with platinum microembolization coils. CONCLUSION: In patients who tolerate temporary balloon occlusion, endovascular treatment of dissecting fusiform aneurysms with platinum microembolization coils is safe and effective therapy.