Odontogenic maxillary sinusitis is an inflammatory process of odontogenic origin, located in the maxillary sinuses and involving the sinus mucosa and sometimes the surrounding bone structures. It is a well-known, usually unilateral condition, which is related to periodontal diseases; abscessеs; radicular cysts; osteomyelitis; iatrogenic and traumatic causes, e.g. the displacement of tooth apices or other foreign bodies into the sinus; root canal overfills; dental implants, penetrating the sinus membrane. This inflammatory process differs sufficiently from sinusitis of other causes in its aetiology, clinical and radiological features, microbiology and treatment. This requires a multidisciplinary approach, combining the work of dentists, oral and maxillofacial surgeons, otorhinolaryngologists, radiologists and microbiologists. The close relation of maxillary sinuses with other anatomical structures (maxillary molars and premolars, paranasal sinuses) should be considered during treatment in order to prevent recurrence, spread to other sinuses and complications. Based on the studied literature, we summarised the most common causes, clinical and radiological aspects, diagnosis and management of odontogenic maxillary sinusitis. Therefore, we created a detailed medical protocol, corresponding to the specific features of this condition.