Anti-N-methyl-D-aspartate receptor encephalitis was described as a clinical entity in 2007. The present case report aims to describe the signs and symptoms, differential diagnosis, treatment and course of a sixteen-year-old boy with this disorder who was hospitalized for almost two months. In addition, we will expose the therapeutic management and the diffculties presented in the handling of neuropsychiatric symptoms, considering the complex context of heterogeneous clinical manifestations caused by this disorder. The authors conducted a PubMed, LILACS and Cochrane search and added supplementary methods to compile the major quantity of evidence to support the clinical decisions. To date no systematic reviews or clinical guidelines about the management of psychiatric symptoms in adolescents with this condition were found. Only case reports and series of cases are available. The quality of evidence is poor as long as there are not analytic studies available. The adolescent presented to the emergency department with confusion, speech disturbances and right brachio-crural hemiparesis. During the course of hospitalization he developed a catatonic syndrome, several episodes of psychomotor agitation, sleep disorders and psychotic symptoms. He received successive immunomodulatory therapy for autoimmune encephalitis and psychiatric medication. He was discharged with recovery almost ad integrum. In conclusion, the diagnosis of anti-rNMDA encephalitis should be suspected in previously healthy adolescents with no psychopathological antecedents who suddenly present psychiatric and neurological symptoms. The evolution and prognosis depend on the early initiation of immunomodulating therapy. Psychiatrists should be aware and suspect this entity rapidly and play an important role as consultants for the management of psychiatric and behavioral disturbances.