Asthma is a heterogeneous disease, generally characterized by chronic inflammation. Severe asthma (SA) affects 5-10% of the asthma population, with the highest values in adolescents (1). The Global Burden of Disease study reported 495,000 asthma deaths worldwide in 2017 (2). In Europe, the mortality rate from asthma can vary according to the disease severity, reaching values of 11.3-14.8/1000 person-years in severe asthmatics (3). According to the European Lung White Book, annual direct costs for asthma (i.e., due to treatment) and indirect costs (i.e., due to the worsening of the quality of life and work disability) were 19.5 billion and 14.4 billion euros at European level in 2011. Individual total annual cost for asthma was € 3400 (4), with about 50% due to SA or difficult to treat asthma (1, 5). The interest of the international scientific community towards SA has increased in the last decades due to its high burden in terms of direct and indirect costs; moreover, there is the need to better understand the mechanisms underlying the severity of asthma and resistance to therapy through a better characterization of the disease itself (6). Many countries have developed regional and/or national disease registries providing valuable information on country-specific epidemiological patterns, natural history, progression, impact and therapeutic risks and benefits (1). In 2020, the International Severe Asthma Registry (ISAR) was established, the first global registry for SA in adults. It is a joint initiative where national registries retain ownership of the data, sharing data in ISAR for research purposes. Its strength comes from the collection of patient-level, anonymous, longitudinal, real, standardized and high-quality data from countries around the world, with the aim of assessing existing knowledge, generating new knowledge and identifying gaps to be fill, thus promoting new lines of research (1). ISAR currently contains data on more than 10000 patients from over 24 countries, including Italy. In Italy, since 2010 registries and initiatives for the monitoring of SA have been developed such as the Italian Registry for severe/uncontrolled asthma (RitA) (7), the Italian network for severe asthma (SANI) (8), the Italian Registry on Severe Asthma (IRSA) (9) and the Italian Network on Pediatric Severe Asthma (IPSAN) (10). Briefly, the RitA Registry was implemented within the AGAVE ("Severe Asthma: epidemiological and clinical cohorts follow up by registry and questionnaires; therapeutic appropriateness and outcome assessment, according to GINA guidelines") project (2010)(2011)(2012)(2013)(2014), funded by AIFA (Agenzia Italiana del Farmaco, the Italian drugs agency) in order to assess the feasibility and M a n u s c r i p t a c c e p t e d f o r p u b l i c a t i o n