Traumatic intracranial pseudoaneurysms in children must be completely secured from the parent artery because of significant morbidity and mortality from the high risk of rebleeding. However, the trapping of the parent artery involves the risk of ischemia changes distal to the trapped artery and the perforator injury. We describe a first case in the literature of successful trapping in the short segment with hydrogel-coated self-expandable coil in a child with a traumatic pericallosal pseudoaneurysm. A 5-year-old boy was admitted to our institution after enduring a blunt trauma with a stuporous mentality. Initial neuroimaging revealed a small hemorrhage in the corpus callosum with subarachnoid hemorrhage. Two weeks later, computed tomogram showed new callosal hemorrhage and a 4.7 x 5-mm pseudoaneurysm of the right pericallosal artery with mental deterioration and weakness of lower extremity. An endovascular short segmental internal trapping (5 mm) of the right pericallosal artery was conducted to save collateral blood flow, using 2 hydrogel-coated self-expandable coils. The cerebral angiogram of immediately after the trapping and at 3 months' follow-up revealed that the aneurysm had been completely obliterated, with successful maintenance of the distal collateral flow from the contralateral pericallosal artery. The patient recovered with good clinical outcome. We suggest that short-segment occlusion by a hydrogel-coated self-expandable coil has become a good alternative for the treatment of traumatic pseudoaneurysms in the distal anterior cerebral artery, although the safety and reliability of this procedure is as yet not definitely proven.