Suspected brain infections, such as encephalitis and meningitis, are critical conditions that require prompt and precise management in the intensive care unit (ICU). These infections can cause severe neurological damage or death if not treated in a timely and appropriate manner. This chapter outlines the management of suspected brain infections, including bacterial, viral, autoimmune, and atypical causes, and is designed to accompany a flowchart for guiding ICU clinicians (Ref. Algorithm 4.1).