Small airway dysfunction (SAD) is a pathological process that affects the bronchioles and non-cartilaginous airways below 2 mm in diameter. This short review presents a link between SAD and IPF. Pathomorphological changes of small airways in fibrotic lungs are discussed. Additionally, functional abnormalities related to SAD measured by spirometry and oscillometry are presented. The problem of early detection and treatment of SAD as a procedure potentially capable of mitigating fibrosis is mentioned.