Bacterial infections of the nervous system are often challenging for the treating physician because sensitivity and specificity of clinical signs do not reach 100%. In patients with neuroborreliosis and bacterial meningitis, investigations of the cerebrospinal fluid are necessary to confirm or rule out the diagnosis. In intracranial and spinal abscesses, the alterations of the cerebrospinal fluid are most often non-specific and imaging and neurosurgical aspiration of purulent material are additionally needed to make the diagnosis. Here, the relevant diagnostic and therapeutic aspects of three common bacterial infections of the central nervous system (neuroborreliosis, bacterial meningitis, and brain abscess) are discussed.