•In patients presenting with clinical manifestations of encephalitis without clinical or laboratory signs of infection, an autoimmune etiology should be suspected.•Antibodies for various neural antigens may coexist, thus a complete and clinically-guided autoimmune panel must be done in suspected cases of autoimmune encephalitis.•Tumor resection, if applicable, combined with high dose steroids and immunotherapy are effective treatment strategies for autoimmune encephalitis with coexisting antibodies.