“Adenoid” the common term for hyperplasia of the pharyngeal tonsil, is a very widespread condition in children 3–6 years of age. The proliferation of lymphatic tissue in this region is so common in children that it can hardly be considered an abnormal condition, and nearly all children have some degree of adenoid hypertrophy due to the immunologic activity of that tissue. As a result, enlarged adenoids should be considered abnormal and treated accordingly only if they are causing symptoms. Not infrequently, the presence and severity of adenoidal symptoms depend on the relationship between the size of the nasopharynx and that of the adenoids. Some authors see that, when typical signs and symptoms of obstructive adenoid hyperplasia are noted, a lateral neck radiograph is unnecessary to confirm a clinically apparent diagnosis. Lateral neck films are limited by the two-dimensional representation of a three-dimensional space and by unreliability in demonstrating small choanal adenoids causing obstruction. When the symptoms and signs do not agree, a computed tomography (CT) is useful. Although studies have demonstrated that symptoms of nasal obstruction are strongly correlated with adenoid size, other studies indicate the importance of a more reliable diagnosis by endoscopy for the dynamic and three-dimensional evaluation of the nasopharynx and of the other intranasal structures