Recent studies have documented carbonyl stress involvement in the pathogenesis of sporadic amyotrophic lateral sclerosis (ALS). The aim of the present study was to assess a role for carbonyl stress in motor neuron degeneration associated with superoxide dismutase-1 (SOD1) mutant familial ALS and its transgenic mouse model, using an immunohistochemical investigation of advanced glycation end products (AGEs) and advanced lipoxidation end products (ALEs). In the spinal cords from six familial ALS patients with SOD1 A4V mutation and six transgenic mice expressing G93A mutant human SOD1, immunoreactivities for N ε -(carboxyethyl)lysine, argpyrimidine, pyrraline and N ε -(carboxymethyl)lysine as AGEs were distinct in almost all of the reactive astrocytes and obscure in the residual neurons, whereas no immunoreactivity for pentosidine as an AGE, or 4-hydroxy-2-nonenal-histidine, malondialdehyde-lysine or acrolein-lysine as ALEs was detectable. Spinal cords from age-matched control humans and mice exhibited no significant immunoreactivities for the examined products. Our results indicate that protein glycation, but not lipid peroxidation, is enhanced in ALS patients with an SOD1 mutation and mutant SOD1 transgenic mice, in which certain AGEs are selectively formed in the spinal cord astrocytes.