In the γ-radiolysis of deoxygenated, N 2 O-saturated aqueous solutions of maltose, lactose, gentiobiose, melibiose, trehalose and sucrose carbohydrate products containing five or six carbon atoms have been identified and their G-values measured. These products originate from the OH radical induced scission of the glycosidic bond of the disaccharides. The nature of the products is in agreement with a reaction scheme proposed previously for the radical induced scission of the glycosidic bond of cellobiose. It involves hydrolysis and the rearrangements of radicals with the free spin next to the glycosidic bond and to the lactol bridge. The nature the glycosidic bond (α, β, 1-4, 1-6, 1-1, 1, 2) has only little influence on the G-values of its scission which range between about 1.9 and 3.5.