BACKGROUND Stereotactic biopsy has been reported as a useful and safety procedure in pediatric patients. In adult patients exist more controversy because a greater number of diagnostic options. OBJECTIVE To demonstrate its usefulness and safety in adult patients with posterior fossa pathology. METHODS From 2006-2014, 23 patients were operated from posterior fossa. Variables: age, gender, state, pre- and postoperative diagnosis, stereotactic device, location and complications. RESULTS 52.2% females and 47.8% males. The location was ponto-mesencephalic 43.5%, cerebellum 39.1%, bulbar 13% and pineal region 4.3%. The preoperative diagnosis was brainstem glioma 78.2%, lymphoma 8.7%, and meningioma, metastasis and abscess 4.3% each one. In 73.9% Zamorano-Dujovni device was used and in 26.1% the CRW. The definitive diagnosis was pilocytic astrocytoma 17.4%, diffuse astrocytoma 13%, inflammatory response 13%, anaplastic astrocytoma 8.7%, gliosis 8.7%, glioblastoma, neuroectodermic primitive tumor, germinoma, pineocytoma and cryptococcosis 4.3% each one. In 17.4% there was no diagnosis. The preoperative diagnosis was concordant in 43.5%. One transient deficit and one pin displacement 4.3% were present. 91.4% without complications. CONCLUSIONS It is a useful, necessary and safety procedure in adult patients.