Introduction: A stereotactic brain biopsy is a procedure in which a small piece of an aberrant brain lesion is taken for microscopic examination. If an unidentified mass is discovered on imaging, this process may be used to precisely diagnose it. In the event that the biopsy specimen is a tumor, the type of tumor and whether it is benign or malignant can be identified using specific microscopic patterns. Treatment can be guided by the information provided by the biopsy results. A stereotactic device precisely guides the placement of surgical instruments during the procedure by using a coordinate-based navigation system that is equipped with the patient's brain images (MRI, CT). Depending on the lesion's location, size, and surgeon preference, stereotaxis can be "framed" or "frameless." Patients and methods: The objective of this study is to carry out a retrospective descriptive analysis of a series of 100 cases followed for brain lesions and benefiting from a stereotactic biopsy, collected at the neurosurgery department of the IBN SINA hospital in RABAT, during the period from 2016 to 2020, in order to implement the contribution and impact of stereotactic biopsy in the management of brain lesions. Results: The patient ages were with an average of 53 years, and a predominance of males. Clinical presentations were dominated by neurological deficits (33%), followed by headaches (30%) and intracranial hypertension syndrome (18%). Lesions were solitary in 79% of cases; among them, 75% were glial tumors, 7% metastases, 5% craniopharyngiomas, and 3% tuberculomas. SBB achieved a diagnostic success rate of 98%. One complication was observed, but no mortality was recorded. Post-operative control scans revealed only transient and benign pneumocephalies. Conclusion: Stereotactic biopsy is not just a technique; it represents the promise of a future where neurosurgery is less invasive, more targeted, and decidedly safer. It represents a central pillar of modern neurosurgery, a technique that combines scientific rigor and advanced technologies.