The evaluation of the disabilities of patients with respiratory disease is regulated by the Spanish Ministry of Labor and Social Security, as are disabilities of any other type. We believe, however, that in respiratory pathologies this evaluation is especially complicated because, as they are chronic processes, they inter-relate with other systems. Furthermore, they tend to have occasional exacerbations; therefore, normal periods may alternate with other periods of important functional limitations. The present document arises from the desire of SEPAR to update this topic and to respond to the requests of respiratory disease patient associations who have asked us to do so. In this paper, we analyze the current situation of work disability legislation as well as the determination of degrees and percentages, including the current criteria for assigning disabilities due to respiratory tract deficiencies. Lastly, we propose work guidelines that would improve the existing scenario and outline this evaluation for specific pathologies.