The major purpose of this manuscript was to provide an upgrading of the guideline Community-acquired bacterial (purulent) meningoencephalitis in adults to an S2k-level according to the Association of the Scientific Medical Societies in Germany (Arbeitsgemeinschaft der wissenschaftlichen medizinischen Fachgesellschaften e.V, AWMF) standards. Ten nominated members of the German Neurological Society (DGN), Swiss Neurological Society (SNG), Austrian Society of Neurology (ÖGN), German Society for Hygiene and Microbiology (DGHM), Paul-Ehrlich-Gesellschaft for Chemotherapy (PEG), German Society of Neuroradiology, German Society for NeuroIntensive- and Emergency Medicine (DGNI), German Society for Infectiology (DGI), German Society for Internal Medicine (DGIM) and German Society for CSF Diagnosis and Clinical Neurochemistry (DGLN) were involved. The executive committees of these societies approved the guideline. These guideline recommendations give an overview of the clinical manifestations and complications of bacterial meningoencephalitis in adults, the diagnostic approach, the management and major prevention strategies.