Objectives: Real situation of adenoiditis and the relationship of adenoiditis with diseases of ear, nose, sinus, throat in middle school students. Subjects: Include 324 students were examined by ENT endoscopy for the diagnosis of adenoiditis and at the middle school Nha Trang of Thai Nguyen city. Methods: Descriptive epidemiological cross study. Results and Conclusions: Adnoiditis have met many students of the middle school accounting for 32.5 percent diseases of ENT, There is no gender difference. No systemic symptoms, Poverty functional symptoms: stuffy nose (15.4 percent), runny nose (10.2 percent). Main synmtoms are: The deposition pus in nose mainly of the following nasal (50.3 percent), pus draining from the dome down the throat (40.4 percent), eardrum concave (38.0 percent). Endoscopy in diagnosis nasopharyngeal adenoid: VA organization to, multiple slot zone, mainly through the development of inflammation and II (34.0 percent) and III (23.8 percent). Adenoiditis level II and III the relationship with pathological middle ear, nose, throat and it causes complication: obstructed eustachian tube (9.5 percent), otitis media with efuntion (9.9 percent), chronic rhinitis (14.5 percent), chronic sinusitis (9.3 percent) and chronic pharyngitis (22.5 percent).