Rhinosinusogenic intracranial complications (ICC) are severe life-threatening disorders. The paper presents the results of treatment in 83 adult patients with pyoinflammatory diseases of the paranasal sinuses (PNS) who were diagnosed with ICC on admission. The patients underwent comprehensive examination using multislice spiral computed tomography of the PNS and brain, lumbar puncture with laboratory cerebrospinal fluid study. Seventy-three (88%) patients were operated on. The results of the performed treatment were as follows: 66 (79.5%) patients were discharged in a satisfactory state; 6 (7.3%) had persistent sequels of central nervous system lesions as spastic hemiparesis. Eleven patients died; hospital mortality was 13.2%. Both local and systemic risk factors influencing the reduction of protective and adaptive functions are of importance in the development of intracranial complications. The complexity of differential diagnosis of ICC is linked to the following clinical features: a patient's significantly severe general status; the depth of central nervous system lesion with marked impairments of consciousness, dysfunctions of vital organs and systems, and intoxication syndrome. The clinical picture of rhinosinusogenic ICCs also shows the following characteristics: a massive purulent nasal and PNS process spreading to the brain tunics, sinuses, and matter; vigorous respiratory tract mucosal swelling; cerebral matter edema with clinical signs of severe neurological disorders; mucosal necrosis and PNS bone wall destruction; purulent brain matter melting with the formation of abscesses; evolving systemic inflammatory response syndrome (sepsis).