A paraneoplastic syndrome associated with anti-N-methyl-D-asparate (NMDA) receptors can initially present as a neurologic or psychiatric disturbance. Removal of the tumor is usually curative, and the syndrome is associated with the presence, rather than the history, of tumor. We present a case in which a 25-year-old, Hispanic woman presented with seizures, memory loss, and unusual behavioral changes. The woman had a teratoma removed 2 months earlier. Because of the time course, a paraneoplastic syndrome was initially considered unlikely. Brain imaging, electroencephalography (EEG) and neurologic work-up were negative. The patient was treated for a suspected somatoform disorder and psychosis. Based on the clinical picture, the working diagnosis was changed to delirium due to paraneoplastic limbic encephalitis. A course of intravenous immunoglobins (IVIg), and high dose steroids was administered. The patient's symptoms improved, and she was discharged home. After discharge, studies came back positive for antibodies against NR1/NR2 of the NMDA receptor.