Objective: To find out the optimal approach to decompress externally the severe injured brain and to avoid possible complications caused by external decompression.Methods: 68 patients who underwent external decompression after traumatic brain injury were admitted into Tianjin Medical University General Hospital for cranioplasty from 1995 to 2001. Complications were retrospectively investigated and analyzed in all patients. The findings were compared between the patients who accepted the decompressive craniectomy in our hospital and in local hospitals. Χ2-test was employed for statistical analysis and complication evaluation. Results: Large craniectomy definitely caused some side effects to patients. Among various complications, several of them showed significantly high incidence (P0.05) between the two groups including dilation or/and migration of lateral ventricle underlying the cranial defect, skin flap concavity, encephalomalacia of the decompressive area, seizure and infection.Conclusions: To reduce the incidence of iatrogenic side effects, surgical craniectomy should be performed according to the strict indication and standard and any abuse should be avoided.