Infections of the nervous system and its belonging structures have often been reported as life-threatening conditions. Purpose: the results of dynamic follow-up and proving of changes in secondary meningoencephalitis from suppurative left maxillary sinusitis are presented using the imaging methods - CT and MRI. Methods: diagnostic imaging (CT, MRI), of acute disease in a 13-year-old child with progressive development and proving of secondary bacterial meningoencephalitis. Result: the control CT after two days showed dynamics in the imaging CT finding with the appearance of changes in the type of brain oedema and development of pansinusitis. The MRI data described corresponded to changes as at meningoencephalitis in progress.Conclusion: The extension of the diagnostic algorithm with MRI, with the administration of intravenous contrast medium, clearly demonstrated changes characteristic of meningoencephalitis.