In the period 2000-2002, 40 patients with odontogenic sinusitis were examined at the Institute for ENT and Maxillofacial Surgery, Clinical Centre of Serbia. Oroantral communication was detected in 40% of the patients, oroantral fistula in 35%, sinus foreign bodies in 15% and other conditions in 10% of the cases. The extraction of the upper lateral teeth was the cause of odontogenic sinusitis in 65% of the cases. Given the specific tooth, the first upper molar was the most often cause of the condition, i.e., in 40% of cases. Odontogenic sinusitis as the complication of the oral cavity surgery was found in 85% of the patients.