We evaluate the efficacy of the coil embolization for tiny ruptured anterior communicating artery (ACoA) aneurysms. Of 21 ruptured ACoA aneurysms with a maximum diameter of 3 mm, coil embolization was successfully carried out in 20 (95%) as the first treatment option. Complete occlusion was achieved in 17 of 20 patients and nearly complete occlusion was realized in 3. There were no treatment-related complications. Seventeen of 20 patients were followed up angiographically for a mean 39.7 months (range 6-72 months), and none of them demonstrated reopening of aneurysm that required additional treatment. Even in tiny ruptured ACoA aneurysms, coil embolization can be a safe and feasible treatment with sophisticated techniques.