Acute suppurative tonsillitis is one of the most common pediatric infectious disease. Numerous attempts have been made to distinguish bacterial from viral tonsillitis based on clinical features. We aim to detect the reasons for penicillin failure in treatment of acute follicular tonsillitis, the emergence of new causative organisms or resistant strains, best ways to diagnose the etiology, and the optimal treatment. The most common pathogen encountered in the etiology of the disease was viral (51.9%), bacterial (40.6%). The most common bacterial pathogen was Haemophilus I. (66.2%), while GABHS represented only 13.9%. Laboratory investigations, specially Culture & Sensitivity Tests were of great benefit in determining the etiology of the disease and the specific treatment to be prescribed.