Abstract: Adenoids, also called nasopharyngeal tonsils, are lymphoid tissues located in the posterior-superior wall of the nasopharynx. Adenoids are prominent in early childhood, and atrophy occurs after age 16. However, regressive adenoidal tissue may show re-proliferation in response to infection or irritants. This makes discrimination between nasopharyngeal carcinoma and benign nasopharyngeal lymphoid tissue difficult. There are many articles about the adenoid-nasopharynx ratio (ANO) in children. However, there is no information on this rate in adulthood. Nasopharynx may be affected by environmental and personal factors such as posterior wall tissue thickness infections, seasonal allergic agents. For this reason, nasopharynx in association with seasons is intended to show normal data for posterior-superior wall thickness. Between August 01 2015 and July 31 2016, files of patients over 18 years of age with lateral cervical radiography were screened. The lateral cervical graphs of 720 patients, 60 patients per month, were evaluated. According to the seasonal variation of ANO ratio, there was no significant difference between summer and autumn, but there was a significant difference between all seasons. The highest rate was found in the winter, the lowest rate in the summer. These results indicate that adenoid tissue is thickened due to upper respiratory tract infections in winter and allergy in spring.