Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)Objective: To verify how efficient respiratory parameters are in the follow-up of subjects with amyotrophic lateral sclerosis (ALS) and to observe possible correlations between respiratory and nutritional functions. Method: Sixteen patients with probable or defined ALS were selected and evaluated over eight months using the following respiratory parameters: spirometry, maximum inspiratory pressure (MIP), maximum expiratory pressure (MEP), arterial gasometry and pulse oximetry; and nutritional parameters such as body mass index (BMI) and percentage weight loss. Results: P(a)CO(2) was a significant parameter to follow up disease evolution (p=0.051). There was significant correlation between MIP and MEP (r: 0.83); BMI and MIP (r: 0.70); BMI and MEP (r: 0.72); pulse oximetry and forced vital capacity (r: 0.57). Conclusion: P(a)CO(2) was shown to be an efficient and significant parameter in the measurement of respiratory impairment; the correlations among MIP, MEP and BMI indicated that these are significant parameters for periodic clinical evaluation.682258262Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)