Objective To investigate the risk factors for post-traumatic hydrocephalus ( PTH) after traumatic brain injury ( TBI ) . Methods A retrospective case control analysis was made on the clinical data of 794 patients with acute TBI admitted to Shenzhen Second People's Hospital between January 2007 and January 2017. There were 639 males and 155 females, aged 1-90 years [(40. 5 ± 18. 6)years]. All patients were followed up for 1 years, and the patients were divided into PTH group (n=46) and non-PTH group (n=748) according to their prognosis. The following information including Glasgow coma score ( GCS ) on admission, pupil reflex, midline shift and cistern compression, subarachnoid hemorrhage ( SAH ) , operation method, decompressive craniectomy, hydrocephalus after operation, intracranial infection, timing of cranioplasty were analyzed using univariate analysis and Logistic regression. Results PTH occurred in 46 patients (5. 8％). Univariate analysis showed that GCS, midline shift, decompressive craniectomy, subdural effusion, timing of cranioplasty and SAH were significantly related to PTH (P<0. 05 or 0. 01). Logistic regression identified low GCS (OR=3. 778), decompressive craniectomy (OR=2. 508), subdural effusion (OR=2. 269), timing of cranioplasty (≥3 months)(OR=10. 478) and SAH (OR=23. 391) as the independent risk factors for PTH (P<0. 05 or 0. 01). Conclusion PTH is a common serious complication of traumatic brain injury, affected by low GCS, decompressive craniectomy, subdural effusion, delayed cranioplasty and SAH.