Exertional dyspnoea among children and adolescents is a common presenting complaint to general practitioners. Exertional dyspnoea is most commonly attributed to exercise-induced bronchoconstriction (EIB), but there are several other causes including hyperventilation syndrome, breathlessness associated with normal exercise limitation and exercise-induced laryngeal obstruction (EILO). The symptoms of EILO include stridor, throat tightness and difficulty on inspiration. If these are mistaken for EIB, children will receive asthma therapy. The underlying mechanism of EILO includes closure of the larynx during high-intensity exercise, which causes a reduction in airflow and breathlessness. This phenomenon is often associated with a background of psychological stress. Historically, a diagnosis of EILO has been considered ‘rare’ though this may be a reflection of under-recognition. Direct visual observation via laryngoscopy is the gold standard for diagnosis of EILO; however, this is rarely available even in specialised centres. Nevertheless, the diagnosis can usually be made by recognising the characteristic clinical pattern. Here we provide recommendations for appropriate investigations for the determination of EILO, together with suggested treatment.© Author(s) (or their employer(s)) 2020. No commercial re-use. See rights and permissions. Published by BMJ.