Pneumocephalus is defined as the presence of air or gas within the cranial cavity. It is usually associated with disruption of the continuity of the skull after head and facial trauma, neuro or otorhinolaryngologic surgery, and rarely, spontaneously. But a case of pneumo-hydrocephlus, a special subtype of pneumocephalus, has been rarely reported. This is a case of a 26-year-old quadriplegic patient who traumatic brain injury with left frontoparietal skull bone fracture and epidural hemorrhage with developed of pneumo-hydrocepahlus in the ventricle 6 months after injury. The mechanism of this case can be explained by the "inverted bottle" hypothesis. Clinical observation suggests that the leakage of cerebrospinal fluid through the ventricle-peritoneal shunt tube caused negative pressure gradient differences resulting in the inflow of outside air into the ventricle through fissures created by concealed fracture of the skull base.