(1) Background: Delirious mania is a neuropsychiatric condition characterized by the rapid onset of delirium, psychosis, and mania. Due to the presence of catatonic signs and symptoms, some authors considered this syndrome to be a specific excited catatonia subtype. Usually, delirious mania is responsive to intravenous benzodiazepines (BZDs) or to electroconvulsive therapy (ECT). (2) Methods: In the present study, we describe the case of a 64-year-old woman with a diagnosis of recurrent major depressive disorder. We assessed the severity of the clinical picture and the response to ECT treatment with the Bush–Francis Catatonia Rating Scale (BFCRS). (3) Results: After eleven sessions of ECT, the patient presented a reduced BFCRS total score, with a resolution of the autonomic abnormalities (temperature, respiratory, and heart rate). (4) Conclusions: These data demonstrate how important it is to diagnose this syndrome as soon as possible to set up an effective therapy, avoiding the use of antipsychotic drugs and preventing potentially fatal complications. The initial administration of BZDs IV and the subsequent ECT application, associated with intensive care of life-threatening general medical conditions, guaranteed us a good level of efficacy in obtaining a complete resolution of the clinical picture.