Background: The nasopharyngeal tonsil, or often just simply the adenoids, form a pair of lymphatic tissue foci that are a component of Waldeyer's ring and are situated on the superoposterior side of the nasopharynx. Objective: This review's objective was to outline the anatomy and physiology of and immunology of the adenoids to understand the diseased states. Methods: We searched Science Direct, Google Scholar, and PubMed for Nasopharyngeal tonsil and Adenoids physiology, immunology and anatomy. The authors also reviewed references from pertinent literature, however only the most recent or comprehensive studies from 1999 to 2023 were included. Documents in languages other than English were disqualified due to lack of translation-related sources. Papers such as unpublished manuscripts, oral presentations, conference abstracts, and dissertations that were not part of larger scientific studies were excluded. Conclusion: Tonsillectomy and/or adenoids may be necessary for patient care if medical therapy fails. Even though tonsil and/or adenoidectomy are common operations, it is important to fully comprehend the architecture of these lymphoepithelial organs in order to reduce the possibility of uncommon but potentially dangerous consequences.