Tonsils are the body’s first line of defense at the oropharyngeal pathway as a part of the Waldeyer's ring. They intercept bacteria and viruses that enter the body through the mouth or nose. Acute tonsillitis is a common infectious disease among sore throat cases, which contribute a significant social-economic impact worldwide that encountered E.N.T. practice. The inflammation in the oropharynx causes sore throat, which may be Acute Tonsillitis, pharyngitis or upper respiratory tract infection. Therefore, the management of this condition is often empirical with the using of antibiotics where the incidence of organism's resistance, due to misusing of antibiotics, is increased. The present study was conducted to identify the prevalence of Tonsillitis among sore throat patients. Study Design: A retrospective descriptive cross-section study, it spanned a 12-months period from Mars 2019 to end of February 2020 on patients visited the Otorhinolaryngology outpatient department (ENT OPD) of Zawia Teaching Hospital (ZTH), Libya. The data gathered from medical records of the hospital, after taking concept of department head manager. During this period 9553 patients consulted in ENT OPD in ZTH, a series of 1160 cases of sore throat was collected, 400 (34%) were Tonsillitis, with female predominance (65.75%) throughout the seasons. 48.5% of patients with tonsillitis were from mid age group (15-45 years) then 41% were from children age group (1-15 years). The peak prevalence of tonsillitis was at March, the highest age group at March were from children, while mid age group shows high prevalence of tonsillitis in July.