Macha and Schwab discuss the study by Rodrigues et al on the time course of hemispheric cerebral volume after decompressive hemicraniectomy (DCH) using hemispheric volumetric measurements of all computed tomography scans (CT scans) performed during inpatient stay before and after DCH. In the study cohort, decompressive hemicraniectomy was performed 41.88 hours after stroke onset. The peak of the hemisphere volume was reached at day 7 after the ischemic event. However, the steepest increase in hemisphere volume was demonstrated in the early phase after stroke onset and 28% of patients showed ipsilateral mydriasis before DHC. This highlights the importance of timely selection of malignant cerebral infarction patients requiring and potentially benefiting from DHC.