Of 115 patients admitted to hospital in 1994-1997 for stomatopharyngeal diphtheria (SPD), 41(35.7%) patients had compensated chronic tonsillitis (CT), while 17(14.8%) patients had decompensated CT. The ENT examinations carried out from the first day of the hospitalization helped to establish CT diagnostic criteria in localized form of SPD. It is shown that CT in diphtheric patients, especially decompensated CT, delays regress of local symptoms, extension of microbiocenotic spectrum and stomatopharynx contamination, prolongs carriage of diphtheric corinobacteria.