The importance of treating traumatic brain injury (TBI) is well known worldwide. Although many studies have been conducted in this topic, there is still much uncertainty about the effectiveness of surgical treatment in TBI. Recently, good randomized controlled trial (RCT) papers about the effectiveness of decompressive craniectomy (DC) in TBI has been published. In this article, we will review the overall contents of the DC (historical base, surgical technic, rationale, complications) and the results of the recently published RCT paper.