Background: Traumatic brain injury (TBI) is a critical public health problem worldwide, constituting a major cause of mortality and morbidity for people of all ages, but especially in the younger population. Decompressive craniectomy (DC) and cisternostomy are surgical procedures commonly used in the management of severe TBI, but their effectiveness in improving outcomes remains controversial. Methods: We conducted a prospective longitudinal study on patients who underwent surgical treatment for severe TBI between 2021 and 2022. The extended Glasgow outcome scale (GOS-E) was used to assess clinical outcome at 2 weeks, 3 months, and 6 months after surgery. Results: The study included 30 patients (21 men and 9 women) who met the inclusion criteria. Among them, 24 patients (80%) underwent DC combined with cisternostomy, while 6 patients (20%) underwent cisternostomy alone. The initial Glasgow Coma Scale (GCS) score at admission ranged from 4 to 8 points, with an average score of 5.9. The overall mortality and overall morbidity was 13.3% and 20%, respectively. The mortality rate was 12.5% and 16.7% in the DC + cisternostomy group and in the cisternostomy alone group, respectively. No statistically significant difference was seen between the two groups in terms of mortality, morbidity and favorable outcome at 2 weeks, 3 months and 6 months. Conclusions: Our preliminary multi-center study shows a good clinical outcome in patients who underwent DC + cisternostomy or cisternostomy alone in both early and long-term follow-up. Larger multi-center randomized trials are needed to establish the effectiveness of cisternostomy in the management of TBI.