Magnetic Resonance Imaging (MRI) has amply shown its usefulness for the evaluation of traumatic cranio-encephalic lesions, particularly those involving the posterior fossa, due to the absence of bone artifacts, the availability of multiplanar sections and the greater sensitivity as regards Computerized Tomography (C. T.). We present an MRI examination of an extra-axial hematoma of the clivus in a child with head trauma, not visible on C. T. scans.