Encephalitis is a group of acute infectious diseases affecting the substance of the brain. They often lead to disability or death, and, therefore, require urgent medical attention. The article discusses the etiology, pathogenesis, and clinical picture of encephalitis, with special attention to the course of this disease after the COVID-19 pandemic. We note the growing number of encephalitis cases, especially of autoimmune variety and those caused by herpes. The possible reason behind this trend is the disruption of operation of the immune system brought by COVID-19, which manifests as a cytokine storm, neuroinflammation, and autoimmune reactions. There are cases of COVID-19-dependent encephalitis described. The pathways taken by SARS-CoV-2 to penetrate into the cells of the central nervous system have not yet been fully studied, although there are hypotheses that this happens both trans-synaptically through mechanoreceptors and chemoreceptors of the respiratory system into the medulla oblongata, and through receptors of the angiotensin converting enzyme 2.