Glutathione S-transferase omega 1 and 2 (GSTO1 and 2) protect from oxidative stress, a possible pathogenic mechanism underlying the pathogenesis of neurodegenerative diseases such as amyotrophic lateral sclerosis (ALS) and Alzheimer's disease. Significant association of age of onset in Alzheimer's patients with GSTO1 and 2 had recently been identified, suggesting a possibly similar association with ALS. In this study 12 Hapmap tagged SNPs in GSTO1 and 2 were genotyped in 251 Caucasian British, Australian and Swedish familial ALS (FALS) cases. No association was found for age of onset and survival of FALS in the British and Australian patients. In the Swedish patients, association for age of onset was found with several SNPs (p = 0.003-0.048). These results suggest a possible effect of the GSTO1 and 2 locus on age of onset of FALS.