The work aimed to analyze the available literature in the international and Russian databases to identify the classification criteria for determining the timing of the primary diagnosis of chronic suppurative otitis media. Materials and methods . A review of the literature on the diagnostic criteria of chronic suppurative otitis media, pathomorphological mechanisms of osteolysis, and factors predicting the chronicity were emphasized, as well as aggressiveness and recurrence of the inflammatory process of the mucous membrane of the middle ear cavity and bone tissue of the petrous pyramid. Based on the literature analyzed, the transition time from acute state to chronic mucous membrane inflammation of the middle ear cavity and persistent perforation formation of the tympanic membrane has not yet been documented, and therefore, the timing of the operation, as a favorable outcome for recovery, is delayed. Results . An analysis of the literature showed that to date, enough classifications, or rather, groups of chronic diseases of the middle ear and its consequences have been published, which indicates the imperfection of the classification criteria for diagnosing chronic suppurative otitis media. Severe pathological changes in the mucous membrane of the middle ear cavities, with purulent fusion, replacement with granulation tissue, and transition of inflammation to the underlying bone tissue with the development of irreversible morphological processes of the temporal bone structures by the type of osteonecrosis, osteoproliferation, and osteosclerosis, which determines the course of chronic purulent otitis media, its outcome, and the risk of complications. Conclusion . Through a combination of the results of literature reviews on the study of clinical experience data from international and Russian specialists, we present the definition of chronic suppurative otitis media as a chronic disease of the middle ear cavity with the formation of a persistent perforation or retraction pockets of the tympanic membrane for a period of 1 month after an episode of acute otitis media with radiographic-tomographic confirmation of latent otoantritis/mastoiditis. Consequently, the diagnosis established enables us to regulate the approach of managing a patient with chronic suppurative otitis media.