Isolated internal iliac artery aneurysms, also called hypogastric aneurysms, are rare and often present with larger dimensions due to their propensity to expand in the pelvis without symptoms. Aneurysm rupture is a serious scenario associated with a significant probability of death and disability regardless of the type of operative repair. Contrast-enhanced computed tomography imaging is the modality of choice to diagnose and surveil hypogastric artery aneurysms and allow planning of open or endovascular treatment. Timely, proactive repair when the aneurysm reaches 3–3.5 cm in diameter in patients of good operative risk allows planning and conducting of an operation to mitigate rupture risk. In patients who are of high operative risk, repair of isolated hypogastric aneurysms can be delayed until they reach 4 or even 5 cm. Although open surgical repair of these aneurysms is effective, less invasive endovascular approaches are associated with lower rates of morbidity and mortality and are thus the preferred method of treatment when possible. Catheter-based treatment usually involves techniques such as embolization of feeding (inflow) and outflow vessels, with or without stent-graft coverage of the main hypogastric artery ostium. When possible, hypogastric artery aneurysm treatment should preserve the contralateral internal iliac artery and as much of the distal pelvic circulation as possible to reduce the risk of ischemic complications. Timely diagnosis, detailed imaging, and proactive repair of isolated hypogastric artery aneurysms, especially with modern endovascular techniques, are effective in reducing the risk of death and disability from this life-threatening condition.