An 18-year-old male athlete was diagnosed with asthma 3 years ago, and his symptoms were well controlled with standard treatment. However, a few months earlier, he had developed dyspnea during strenuous exertion and was unable to participate in athletic activities. Laryngoscopy was performed immediately after the onset of symptoms due to high-intensity exercise, and a diagnosis of exercise-induced laryngeal obstruction (EILO) was made based on the finding of adduction of the aryepiglottic folds with stridor on inspiration. Initially, the patient was trained in breathing and rescue techniques to manage the symptoms of dyspnea, but this was not completely successful. He subsequently underwent surgical treatment and is now able to participate in athletic activities. Differentiating EILO from exercise-induced asthma is important, and the following factors are helpful in the diagnosis: stridor on inspiration, rapid improvement of symptoms after cessation of exercise, and ineffectiveness of bronchodilators prior to exercise.