In order to determine the risk factors of odontogenic maxillary sinusitis, a total number of 40 patients with this pathological condition was examined in three-year period. Oroantral communication was detected in 40% of patients, oroantral fistula in 25%, sinus foreign bodies in 15% and other pathological conditions in 10% of cases. The extraction of the upper lateral teeth was the cause of odontogenic sinusitis in 65% patients. Given the specific tooth, the first upper molar was the most common cause of the condition, i.e. in 40% of cases. It may be concluded that odontogenic sinusitis is the complication of the oral cavity surgery in 85% of patients, what should be taken into consideration in prevention.