In the work there are shown the results of a "case control" study carried out in a children collectivity (preschool children and school-children), regarding the action of an aqueous propolis extract, NIVCRISOL, in acute and chronic inflammatory diseases of the upper airways. The preparation, which had a rich content of flavonoids, was administered to a group of preschool children and school-children treated during the whole cold season 1994-1995. The monitoring of the subgroups investigated was performed by clinical observation of the health state and recording of the incidence of symptoms characteristic to acute or chronic rhinopharyngeal diseases, as well as by a periodical laboratory examination for the detection and characterization of viral, microbial and fungal germs carriage. The analysis of the data obtained pointed out the favourable effects of this local treatment, expressed by lowering of the number of cases with acute or chronic symptoms, and decrease and sometimes suppression of the viral-microbial flora carriage of the upper airways. These positive results, the good tolerance of the preparation, the advantages of the therapy with natural products and more economic criteria entitle us to propose the administration of this preparation as an adjuvant medication in the local treatment of some clinical forms of acute or chronic rhinopharyngeal diseases.