It can be concluded on the base of data from literature and of our own results, that the metabolism of glycine is localized mainly in liver tissue. The main catabolic pathway of nutritional glycine proceeds via the glycine-cleavage enzyme, serinehydroxymethyltransferase and serinedehydratase or serine-pyruvate aminotransferase and via serine and pyruvate. The physiological significance of this metabolic pathway is estimated. The catabolism via the C1-pool is limited by the regeneration rate of tetrahydrofolic acid. Other pathways (via glyoxylate, SHEMIN-cycle, aminoacetone cycle) are only of minor significance for the catabolism of glycine originating from food.