Magnesium (Mg) is the second most important intracellular cation that is needed for a broad variety of physiological functions. Disturbances in Mg body status, which may be induced by environmental contaminants, life style and manner of nutrition, can create serious negative consequences for health. One of the factors affecting Mg homeostasis is excessive ethanol consumption. Interactions between ethanol and Mg can take place at different stages of Mg metabolism (absorption, distribution in the organism and excretion of this element) as well as at the stage of its biological functions. Ethanol ingestion leads to serious disturbances in Mg metabolism on the one hand, while dietary Mg intake has been reported to influence the metabolism and toxicity of ethanol on the other. Experimental data show that Mg supplementation may prevent or reduce adverse effects of ethanol action in animals, whereas its deficiency can intensify ethanol toxicity. In this review, the interactions between ethanol and Mg in humans and animals are discussed on the basis of the available clinical, epidemiological and experimental data, against the background of common ethanol consumption and insufficient Mg dietary intake in the general population.