This study aimed to examine feasibility of inspiratory muscle strength tests, such as maximal inspiratory pressure (MIP) and sniff nasal inspiratory pressure (SNIP) in adult patients affected by spinal muscular atrophy (SMA), as well as their ability, along with forced vital capacity (FVC), to predict noninvasive ventilation (NIV) needs. Additionally, we evaluated feasibility and effectiveness of respiratory oscillometric measurements in the same patients. Twenty patients were retrospectively evaluated. NIV requirement was considered as peak nocturnal transcutaneous PCO