Intracranial aneurysm (ICA) is a common condition but with a high mortality rate when rupture occurs. The treatment of ruptured or unruptured ICA, especially with an endovascular approach, has been evolving rapidly. The current generally accepted opinion suggests that endovascular embolization is an effective technique for preventing the recurrence of aneurysm rupture, but the rebleeding rate after endovascular embolization is found to be higher than that after surgical clipping. In addition, long-term follow-up data are required for the evaluation of the effectiveness of endovascular treatment in unruptured ICA. This review presents the current understanding of ICA, the selection of optimal treatment approaches, and in particular, the advances in endovascular embolization in the treatment of ICA, including embolic materials, therapeutic and assisting techniques, long-term effectiveness, and limitations.