We report the case of a 61-year-old man with amyotrophic lateral sclerosis presenting with respiratory failure requiring long-term mechanical ventilation. Diagnostic difficulties are discussed along with the circumstances that give rise to suspicion of neuromuscular disease in a context of respiratory failure of unknown cause. The patient is at present in stable condition after 6 months of domiciliary mechanical ventilation. The treatment options in such cases and their indications are discussed.