Maxillary sinus inflammation, when untreated or incorrectly treated, may extend locoregionally, the remaining paranasal sinuses being the first affected anatomical structures. This is why the understanding of the inflammatory pathology of the maxillary sinus, and particularly of the complications it can generate, is extremely important. The purpose of this presentation is to point out that inflammations of the paranasal sinuses are susceptible to develop complications in certain conditions and threaten the patient's life due to the proximity of vital structures. This is the case of a 16 years old male patient who developed a left maxillary and frontal sinusitis, complicated with cerebral abscess. Early detection, multidisciplinary approach and proper indication of surgical treatment, as well as early suspicion of complication, especially in young male adolescents, are extremely important.