Post-traumatic pneumoorbitus is generally a benign, self limiting condition. However, if a fracture produces ball-valve effect allowing air to enter but not leave the orbit, then extremely high intraorbital pressure and visual loss are possible. A 30- year old man with loss of vision because of tension pneumoorbitus who was successfully treated by craniotomy and in whom the defect in lamina papyracea was repaired by muscle packing is presented here.