APOE epsilon4 allele is associated with poorer outcome in degenerative neurological diseases. Its role in amyotrophic lateral sclerosis (ALS) is still unclear. The aim of the present study was to further analyze the association of APOE epsilon4 allele with progression and survival of ALS. One hundred consecutive ALS patients (53 males) and 133 controls were genotyped for the APOE epsilon4 allele. The association of this allele with survival to death or tracheostomy was analyzed by Kaplan-Meier survival analysis. The frequency of the APOE epsilon4 allele in ALS patients was slightly higher (15.1%) than in the control group (10.9%). Patients with or without an APOE epsilon4 allele had a similar age of onset and frequency of bulbar onset. There was a significant shortening of the 50% probability of survival (by 32 months) in patients carrying the APOE epsilon4 allele (p=0.03). In conclusion, carrying an APOE epsilon4 allele is a poor prognostic factor in ALS. This is compatible with a role of apolipoprotein on neuronal survival and repair.