The tonsils form part of a circular band of adenoid tissue which guards the opening into the digestive and respiratory tubes, known as Waldeyer’s ring. The anterior part of the ring is formed by the submucous lymphoid clusters (lingual tonsil) on the posterior part of the tongue; the lateral portions consist of the palatine tonsils and the lymphoid tissue in the vicinity of the auditory tubes, while the ring is completed behind by the pharyngeal tonsil on the posterior wall of the pharynx. In the intervals between these main smaller collections of lymphoid tissue are found. This paper intends to give to the clinician an anatomical review about the subject.