Tonsillitis is inflammation of the pharyngeal tonsils. The inflammation usually extends to the adenoid and the lingual tonsils; therefore, the term pharyngitis may also be used. Most cases of bacterial tonsillitis are caused by group A betahemolytic Streptococcus pyogenes (GABHS). Tonsillitis remains one of the common diseases in developing countries. Prompt and appropriate treatment based on the knowledge of the causative microbiota and their antimicrobial susceptibility pattern will improve the treatment outcome and reduce time and resources spent on treatment. This study aims to the main organisms responsible for tonsillitis, their sensitivity and resistance to antibiotics, one hundred and forty five patients with Acute and chronic tonsillitis who presented to the (ENT) department in ENT in Al-Husain Teaching Hospital, Samawah city, from March 2021 to April 2022 were prospectively studied, The proportion of the cultures that were positive of significant growth, the proportion of these positive isolates that were Streptococcus spp. and varied sensitivity pattern obtained underpinned the important to advocate for culture isolates and susceptibility pattern guided treatment.