Central nervous system (CNS) infections are a group of diseases, where meningitis (associated or not to neurosurgical interventions) and bacterial ventriculitis have been studied for many years in order to establish early diagnosis methods through direct therapy to reduce morbidity and mortality in this population. Analysis of the cerebrospinal fluid (CSF) is an important source of information for diagnosis of neuroinfection. Lactate concentration in the cerebrospinal fluid has a value independent of plasma because it does not cross the blood-brain barrier, therefore, constitutes the end-product of the bacterial anaerobic glycolysis being the primary source of lactate in the CSF. Therefore, it has a great tool in the diagnostic approach of bacterial meningitis, however, reference values ​​are not warranted. Objective: The authors present the latest scientific evidence on the use of lactate as a diagnostic method for two neurological pathologies with highest incidence on population, establishing a translational approach to clinical practice. Methods: A comprehensive literature review was carried out. We describe the results of a structured search based on keywords infection, meningitis, ventriculitis, bacterial, cerebrospinal fluid, and lactate, vía Medline, Scopus, WoS, EMBASE, and LATINDEX databases. Conclusion: Lactate in a CSF sample is useful to determine the bacterial etiology in patients with suspected meningitis. CSF lactate value equal or higher than 4 mmol/l could indicate bacterial meningitis about 90% of probability. Lactate value is identical in patients with ventriculitis; however, it cannot be established as neuroinfection, therefore, we should use another diagnostic method. Objective: This work will present the updated scientific evidence regarding the use of lactate as a diagnostic method for two neurological entities with high incidence in our population, establishing a translational approach to our clinical practice. Methods: A comprehensive literature review was carried out we wrote the results of a structured search with the keywords infection, meningitis, ventriculitis, bacterial, cerebrospinal fluid, and lactate, in both English and Spanish within the Medline, Scopus, WoS, EMBASE, and LATINDEX databases. Conclusion: Measuring lactate in a CSF sample is useful to determine the bacterial etiology in patients with suspected meningitis, a CSF lactate value greater than or equal to 4 mmol / l means that a patient will have bacterial meningitis with certainty greater than 90% However, the lactate value is the same in a patient with ventriculitis, it cannot be established with total certainty that it is a neuroinfection, therefore, we should use some other diagnostic method