Adulterated alcoholic beverages are legal alcoholic products that have been illicitly tampered with, for instance, by criminally diluting them with water, purposely putting them into new containers to conceal their true origin or adding toxic substances to manipulate the qualities of alcoholic beverages. The collection of cases at the Department of Pharmacology and Toxicology, University of Iceland, which contains examples of each category of adulteration, is the basis of the present article. Especially noteworthy are cases involving the toxic substances methanol and/or ethylene glycol. Methanol has been added to legally produced wines to increase their „bite“ and ethylene glycol to increase their sweetness. Adding these substances to wine has resulted in poisoning or death in other countries, but not in Iceland as far as is known.