Cavernous and petrous internal carotid artery (ICA) aneurysms have similar clinical characteristics, making it feasible to discuss these two types of aneurysms together. Currently, endovascular treatment (EVT) is favorable for these lesions. However, EVT techniques are complex. A review is necessary to explain EVT techniques for various cavernous and petrous ICA aneurysms. Based on the findings of this review and our experience, cavernous and petrous ICA aneurysms have complex classifications. Most lesions have a benign natural history, and EVT is needed only for ruptured, symptomatic or growing lesions. For small and medium sidewalled cavernous and petrous ICA aneurysms, selective coiling can be used. There are many methods for treating large or giant fusiform lesions, such as flow diverter (FD) and covered stent deployments and parent artery occlusion (PAO). Currently, FD deployment has revolutionized the management of cavernous and petrous ICA aneurysms. PAO can only be used in select cases. FDs with surface modifications are promising for treating cavernous and petrous ICA aneurysms. In general, EVT can yield good neurologic and adequate angiographic outcomes in appropriate patients with cavernous and petrous ICA aneurysms.