The objective of the present study was to elucidate the spectrum of the pathogenic agents responsible for the development of acute suppurative otitis media in the children of the preschool age and to reveal the specific clinical features of this disease depending on its etiological factors. The study involved 138 patients (186 ears) of either sex at the age from 1 year to 84 months who presented with acute suppurative otitis media. The following methods were employed for the purpose of the study: analysis of the patients’ complaints and the past medical histories, examination of the ENT organs, microbiological (bacteriological and virological) studies of secretion from the tympanic cavity, diagnostic endoscopy of the nasal cavity and nasopharynx, laboratory investigations. The study allowed to reveal the characteristic clinical manifestations of the pathology of interest depending on its etiology.