Objective: Case presentation and subsequent diagnostic and therapeutic procedure of autoimmune encephalitis caused by the presence of ovarian teratoma. Case report: We describe the case of a young woman with symptoms of an acute psychotic attack unresponsive to antipsychotic treatment. Anti-N-methyl-D-aspartate receptor encephalitis was diagnosed within the interdisciplinary cooperation at the University Hospital in Olomouc. Conclusion: This type of rare and potentially fatal paraneoplastic limbic encephalitis occurs predominantly in young women. Due to the high variability of neuropsychiatric symptoms, the diagnosis of the disease is very difficult, and therefore patients are often primarily incorrectly treated for other neurological or psychiatric diseases. The most prognostically important part is early diagnosis and adequate therapy. Key words: ovarian teratoma – anti-N-methyl-D-aspartate receptor encephalitis (anti-NMDAR encephalitis) – paraneoplastic syndrome