Ethanol-disulfiram reaction (EDR) is a rare but potentially life-threatening condition characterized by a constellation of symptoms, including flushing, hypotension, tachycardia, nausea, and vomiting. We report the case of a 52-year-old male patient who presented with acute hemodynamic instability after inadvertent alcohol consumption while on disulfiram therapy for alcohol dependence. The patient exhibited signs of shock, including hypotension and hyperlactatemia, but responded promptly to fluid resuscitation and transient vasopressor support. A detailed history confirmed the diagnosis of EDR. This case highlights the importance of recognizing EDR as a differential diagnosis in patients with acute hemodynamic instability and a relevant clinical history. Early identification and supportive management are crucial for favorable outcomes.