Diphtheria is one of the significant health problems in developing countries. It is not only seen in children but also in adults due to low immunization coverage in our country. This study is aimed at analyzing the outbreak of diphtheria at GIMS Kalaburagi in Aug 2019. It mainly involves the upper airway tract and accounts for mortality of 5-10% generally but sometimes even as high as 20% mortality is seen in children below 5 years of age. Despite of universal immunization program(UIP) of diphtheria vaccine many cases of re-emergence or new cases of diphtheria are being detected every year. Hence it becomes necessary for us to study and analyze the diphtheria outbreak and review the literature.