Catatonia is a common neuropsychiatric syndrome. There is a life-threatening subtype of this disease known as malignant catatonia. One of the hypotheses regarding the pathogenesis is an imbalance of multiple neurotransmitters (gaba, glutamate and dopamine). The first step in treatment is to administer benzodiazepines; if the response is insufficient, the treatment can be replaced by electroconvulsive therapy (ect). So far, there is no consensus with regard to the tertiary treatment step. On the basis of a case report we describe the beneficial effects of administering an nmda receptor antagonist, amantadine, as the tertiary step for treating a patient with treatment-resistant malignant catatonia.