Immature teratomas represent only the 1% of ovarian teratomas, and they are the third most common primitive germ cell tumor; generally, they are congenital lesions and affect mainly the first 2 decades. We present the case of a 7-year-old child who came at our attention because of an acute low abdominal pain due to the torsion of an ovarian immature grade 1 teratoma on its pedicle. After ultrasound in the emergency department, preoperative evaluation was done by performing a magnetic resonance study, whose findings helped in suggesting the curative approach. The magnetic resonance imaging characteristics of the neoplasm are reviewed and correlated with histopathologic findings. As it was highlighted in our case, magnetic resonance imaging may be part of the diagnostic approach of this rare disease entity also in a small child in emergency.