A clinical survey of 2,021 cases which were diagnosed as diphtheria in otolaryngologic department of Seoul Central City Hospital, or brought to the hospital for isolation and proper care from other clinics during the past 5 years from January 1961 to March 1966, is reported and discussed. The results are ; 1) The patients complaining laryngeal symptoms and/or sore throats were mostly male predominant (54%), under 5 years of age (60%) and were prevalent during winter months (51%). Annual increase in total number and especially adult cases were noted. 2) Lesser numbers of fauceal diphtheria cases which are supposed to be more prevalent, suggested that the most of them might have been overlooked or treated as a simple sore throats. Difficulty of differenciation of laryngeal diphtheria from the other acute laryngitis is one of the important problems. 3) D.A.T., antibiotics and tracheostomy for dyspneic patients were of great value. Deaths (5%) and sequelae (3%) were comparatively rare in early handled cases.