In the γ-radiolysis of N2O saturated aqueous solutions of meso-erythritol (10-2 mol/1) the following products (G-values) are formed: erythrose (1) (1.3), erythrulose (2) (1.4), 2-deoxy-tetrose (3) (0.70), butanediol- (3,4)-on- (2) (4) (0.75), butanediol- (1,4) -on- (2) (5) (~0.1), glycerol aldehyde (6) (∼0.1), glycol aldehyde (?) (7) (<0.1) and dimers (8) (0.45). The formation of the products can be explained by the attack of the water radicals (OH and H) on the meso-erythritol to give primarily meso-erythritol radicals. These radicals may disproportionate (products: 1 and 2), eliminate water, or fragment. The dimers 8 and the products 3-5 contain deoxy-groups attached to a carbonyl function. Their precursors are meso-erythritol radicals which have split off water before dimerization or disproportionation. 6 and 7 seem to arise from β-fragmentation processes of the primary meso-erythritol radicals.