OBJECTIVE AND IMPORTANCE:The intradural extension of a sacrococcygeal teratoma is rare and has been reported previously in only two cases. We present a case of a sacrococcygeal teratoma with an intradural and extramedullary extension.CLINICAL PRESENTATION:The patient was a full-term female infant, born with a sacral mass. Ultrasonography, computed tomography, and magnetic resonance imaging showed an intraspinal extension.INTERVENTION:The operation confirmed the extension of the mass up to the T4 level, and total tumor removal was achieved. The pathological examination showed a mature teratoma.CONCLUSION:The postoperative course was uneventful, and at the 3-year follow-up examination, the patient had experienced normal growth without deficit in the lower limbs but had a neurogenic bladder. Magnetic resonance imaging disclosed no tumor recurrence. This case represents the third case in the literature of an intradural extension of a sacrococcygeal teratoma and the first one with an extramedullary component so extensive.