Background: People with intellectual disability have limited access to diagnostic procedures due to poor collaboration and inability to understand instructions. There is a need to render diagnostic services more accessible to individuals with intellectual disability to ensure them the best possible level of clinical management. In the case of suspected asthma and a patient’s inability to perform Spirometry, Impulse Oscillometry (IOS) can be used to confirm the diagnosis. Objective: Our aim was to identify strategies to improve the performance of Impulse Oscillometry in a patient with severe cognitive disability and to confirm the clinical suspicion of asthma. Materials and Methods: To ensure the patient’s maximum level of active participation personalized instruction and training were provided prior to the actual exam in order to familiarize him with the procedure. The exam was conducted according to technical standards published in 2020 by the European Respiratory Society for Respiratory Oscillometry. Results: A 41-year-old patient with severe intellectual disability, a recent episode of Covid 19 pneumonia and suspected asthma performed an initial IOS test which did not allow for confirmation of the diagnostic hypothesis. The second IOS test, conducted following a one-month period of training, confirmed the diagnosis of asthma Conclusions: The difficulties encountered by the patient in performing the IOS test efficiently were resolved by implementing adapted training strategies to meet the patient’s special needs, without compromising test quality.