Decompressive craniectomy (DC) following brain injury can induce complications (hemorrhage, infection, and hygroma). It is then considered as a last-tier therapy, and can be deleteriously delayed. Focal neuromonitoring (microdialysis and PtiO2) can help clinicians to decide bedside to perform DC in case of intracranial pressure (ICP) around 20 to 25 mmHg despite maximal medical treatment. This was the case of a hunter, brain injured by gunshot. DC was performed at day 6, because of unstable ICP, ischemic trend of PtiO2, and decreased cerebral glucose but normal lactate/pyruvate ratio. His evolution was good despite left hemiplegia due to initial injury.