BACKGROUND Basal cisternostomy (BC) is increasingly utilized for intracranial pressure (ICP) management in severe traumatic brain injury (TBI), particularly by neurosurgeons in some high-incidence regions like India and China. It is performed as an adjunct to decompressive craniectomy (DC) or as a stand-alone procedure with bone flap replacement if brain laxity permits after basal cisternal drain placement. Emerging research from regions where this method is used supports its efficacy for ICP control. OBSERVATIONS A 17-year-old male was involved in a severe road traffic accident. He presented with a Glasgow Coma Scale score of 5 and bilaterally dilated, nonreactive pupils. CT revealed a left acute subdural hematoma (ASDH) with significant midline shift, severe global brain edema, effaced basal cisterns, and brainstem compression signs. Emergency BC was performed, followed by ASDH evacuation. The bone flap was replaced. Postoperatively, the patient showed remarkable recovery, with extubation on day 2 and early mobilization. By day 7, he was walking with assistance, and by discharge on day 13, he exhibited only mild word-finding difficulty, which improved significantly at follow-up. LESSONS This case highlights the potential of BC as an alternative or adjunct to DC in severe TBI, emphasizing the need for larger, multicenter studies to validate its efficacy. https://thejns.org/doi/10.3171/CASE25170