Acute pernicious beriberi heart disease (APBHD) remains a frequently unrecognized clinical entity in alcoholics which, if not recognized and promptly treated, may cause the patient's death. Prompt and rapid reversal of the underlying metabolic defect can be accomplished with intravenous thiamine administration if the accompanying metabolic acidosis is corrected concomitantly. The pathognomonic response to thiamine is characterized by four clinical stages: hypotension and metabolic acidosis, high output cardiac failure, hypertension, and diuresis. The clinical picture of metabolic acidosis and shock in any nondiabetic alcoholic patient should always suggest the possibility of APBHD and when in doubt, a trial of intravenous thiamine is indicated. APBHD may be a more common medical emergency than is generally appreciated.