The evaluation of syncopal children or adolescents relies heavily on a thorough, detailed history and physical examination. All syncope associated with exercise or exertion must be considered dangerous. The ECG is mandatory, but other laboratory tests are generally of limited value unless guided by pertinent positives or negatives in the history and physical examination. The ECG allows screening for dysrhythmias, such as Wolff-Parkinson-White syndrome, heart block, and long QT syndrome, as well as hypertrophic cardiomyopathies and myocarditis. Tilt table testing can be useful in selecting therapy by demonstrating the physiologic response leading to syncope in an individual patient. The most common type of syncope in otherwise healthy children and adolescents is neurocardiogenic or vasodepressor syncope, which is a benign and transient condition. Because syncope can be a predictor of sudden cardiac death, it must be taken seriously, and appropriate screening must be performed.