The population in Japan is aging at a faster rate than in other countries in the world. It is speculated that the number of patients with late-onset amyotrophic lateral sclerosis (ALS) will increase even more in the future. However, few studies have been undertaken on the characteristics of patients with late-onset ALS in Japan. This study sought to investigate the clinical features of patients with late-onset ALS compared with those with early-onset ALS using the progression rate (ΔFS).Forty-five patients with sporadic ALS were divided into 2 groups: 23 patients with early-onset of ALS (<65 years; early onset) and 22 patients with late-onset ALS (≥65 years; late onset). Every patient was followed up from the time of initial diagnosis to the primary endpoint (death or time culminating in death without tracheostomy or ventilation assistance including noninvasive positive pressure ventilation) or for at least 48 months after initial diagnosis.ΔFS in the patient group with late onset was significantly higher than that of the group with early onset (p=0.010). Survival of patients with late onset was significantly decreased compared to that of patients with early onset (p=0.031).Our finding suggested that patients with late-onset ALS showed more rapid disease progression than those with early-onset ALS using ΔFS.