The objective of the present work was to study peculiarities of the clinical picture and the results of the treatment of rhinosinusogenic complications in children and to evaluate the diagnostic and prognostic significance of systemic inflammatory response syndrome (SIRS) and other mediators of inflammation. A total of 103 case histories were available for the analysis. The age of the patients varied from 1 month to 15 years. Pyogenic orbital pathology was documented in 55 (53.4%) children, eyelid abscess and subperiosteal abscess in 13 (23.6%), orbital phlegmona and retrobulbar abscess in 38 (69.1%), osteomyelitis of the facial skeleton in 4 (10.5%), and intracracnial complications in 48 (46.6%) children (including pachimeningitis/extradural abscess in 5, meningitis in 10, meningoencephalitis in 6, subdural empyema in 12, cavernous sinus abscess in 8, and cerebral abscess in 7 patients). SIRS was diagnosed in 24 (42.8%) children with orbital complications and in 100% of the patients suffering intracranial pathology. It was shown that a rise in the C-reactive peptide level to above 50 mg/l in conjunction with two or more signs of SIRS may serve as a sensitive diagnostic criterion for the severe infection while a decrease in C-reactive protein to below 50 mg/l within the first days of the disease is a reliable prognostic factor of its favourable outcome. The blood level C-reactive protein in the patients presenting with intracranial complications exceeded 0.1 mcg/l and continued to increase in proportion to the severity of the disease. A total of 43 (41.8%) children were available for the long-term follow-up (seven of them developed a relapse of frontitis that required reoperation, one patient presenting with nasal liquorrhea needed plastic closure of the liquor fistula, and one more died after the one-year follow-up period had elapsed because of polyorgan insufficiency).