Introduction. Mastoiditis is an acute or chronic inflammatory disease of the middle ear, which occurs as a result of inflammatory processes of bacterial origin of mastoid cells. It usually occurs in the absence of treatment or improper treatment of acute or chronic otitis media and consists of the spread of the infection from the middle ear to the surrounding bone - the mastoid process. Mastoiditis with a diverse clinical picture may be able to cause life-threatening complications under certain conditions. Aim of study. Mastoiditis is a common complication of acute otitis media, which manifests itself in several clinical forms that can cause complications. Mastoiditis is more common in a more vulnerable age group, which requires the application of emergency medical tactics to prevent severe complications. Methods and materials. This literary review was based on literature findings, articles related to recent statistical evidence on mastoiditis. All relevant information was obtained from the literature review of open access databases. Results. Currently, acute mastoiditis is a rare disease. Acute mastoiditis is a disease of very young people. Its incidence in children under 14 is given in the literature as 1.2-4.2 per 100,000 children per year. In most cases, children are 1-3 years old. Because children are more susceptible to middle ear infections, they are at increased risk of developing acute mastoiditis compared to adults. Mastoiditis is more common in children and people with nasopharyngeal disorders and a history of recurrent otitis media. Untreated otitis media increases the risk of acute mastoiditis and is the cause of higher incidence in developing countries. The progression of acute mastoiditis can have devastating consequences. Due to the location of the mastoid process, opportunistic infections can spread inward, intracranial, or outward, peripherally. Intracranial manifestations of acute mastoiditis occur in 6 to 23% of cases, these complications may include sigmoid sinus thrombosis, epidural abscess and meningitis. Extracranial complications of acute mastoiditis include the following: subperiosteal abscess, facial nerve palsy, labyrinthitis Gradenigo syndrome, Bezold abscess. In order to prevent the possible complications of mastoiditis as early as possible, it is necessary to apply surgical treatment - mastoidectomy, which in turn has several variations: simple mastoidectomy, radical mastoidectomy, modified radical mastoidectomy. Thus, the surgical treatment itself or in combination with the drug treatment favors the quality of the otorhinolaryngological system and of the whole organism. Conclusion. The application of effective curative tactics and as early as possible, according to the clinical form of mastoiditis, stops the appearance of severe complications that can be life threatening under certain conditions.