BACKGROUND AND PURPOSE: Posterior communicating artery aneurysms with oculomotor nerve palsy may imply sudden enlargement of the aneurysm sac and have a high risk of rupture. Our aim was to identify the morphologic and hemodynamic parameters in this special period of aneurysm progression and to assess related rupture risk indices. MATERIALS AND METHODS: We analyzed the morphologic and hemodynamic parameters of 9 unruptured posterior communicating artery aneurysms with oculomotor nerve palsy and 9 ruptured ones. The morphologic parameters were measured and calculated from patient-specific 3D rotational angiographic images, and pulsatile computational fluid dynamic simulation was then performed for hemodynamic parameters. RESULTS: There was no significant statistical difference between the 2 groups in size, aspect ratio, size ratio, aneurysm angle, or vessel angle; analysis only demonstrated a significantly lower wall shear stress of the aneurysm wall in the symptomatic unruptured group in hemodynamics (P = .024), whereas there were no differences in wall shear stress of the parent artery, low wall shear stress area, and oscillatory shear index. CONCLUSIONS: From morphologic and hemodynamic perspectives, we demonstrated that posterior communicating artery aneurysms with oculomotor nerve palsy had characteristics similar to those of ruptured ones, except for lower wall shear stress on the aneurysm wall, which might indicate an important role in aneurysm rupture.