we report the case of an 11-year-old girl with sickle cell disease who presented to the emergency room after being hit by a mud pie in the left frontal region. examination evidenced left eye proptosis, eyelid swelling, reduced visual acuity and afferent pupillary defect, without any inflammatory signs such as fever, hyperemia or tenderness. computed tomography of the orbits showed a large superomedial subperiosteal hematoma in the left orbit. the patient was treated with canthotomy, cantholysis and surgical draining of the hematoma. two days after drainage she persisted with a subperiosteal hematoma and low visual acuity. a wide exploration of the orbital roof through a lid crease approach disclosed a thickened superior orbital rim with multiple bone defects along the roof and with continuous bleeding. hemostasis was accomplished with bone wax. orbital compression was resolved and the patient recovered her previous normal visual acuity.