This article encompasses a discussion of the clinical presentation and features as various diagnostic modalites of bronchoprovocation and differential diagnosis used in screening for asthma in the athlete. A comparative analysis of these modalities, including questionnaire, treadmill, eucapneic hyperventilation, as well as field challenge, is provided with sensitivities and specificities, predictive value, and application to clinical practice. The indication and mechanics of each diagnostic modality is discussed, providing the clinician with a comprehensive understanding of the principles and procedures used to diagnosis asthma in the athlete.