The intermediate respiratory care units (UCRI) are areas of monitoring and specialized care of patients with acute or chronic-exacerbated respiratory failure, whose severity does not require admission to an intensive care unit, but which due to their complexity cannot be treated in conventional hospitalization. Although the COVID-19 pandemic has proven its usefulness in the management of critical respiratory patients, the historical trajectory of the UCRI comes from many years ago, in which its cost-effectiveness has been demonstrated by far. This document presents a series of questions and answers on the history of the UCRI, in addition to the criteria for admission, infrastructure, human and technical resources, and the types of existing Units. Within the UCRI year 2021-2022 designated by the Spanish Society of Pneumology and Thoracic Surgery, any scientific dissemination linked to the in-depth knowledge of these units is timely, where multidisciplinarity and the work of professionals related to the care of critical respiratory patients converge., (© 2022 Published by Elsevier España, S.L.U. on behalf of Sociedad Española de Neumología y Cirugía Torácica (SEPAR).)