Decompressive craniectomy(DC)for intracranial hypertension after traumatic brain injury(TBI)can be divided into two treatment strategies: primary DC and secondary DC. DC has an important intracranial pressure-lowering effect; however, the standard treatment has not been established because the treatment policy with respect to surgical indication, optimal timing, and surgical method are often determined according to the empirical rules of each institution. In addition, the effects of DC on clinical outcomes remain unknown. Recently, the results of a large multicenter randomized controlled trial(RCT)about the effects of secondary DC for severe head trauma have been published. The study showed that secondary DC improved the mortality rate but had no effect on functional prognosis. Another RCT about the effects of primary DC for TBI is ongoing and the results are awaited. We herein describe the indications, surgical methods, and issues of DC for TBI based on the results of these clinical trials with a high level of evidence.