Odontogenic sinusitis is a well-recognized condition and accounts for approximately 10% to 12% of cases of maxillary sinusitis. An odontogenic source should be considered in individuals with symptoms of maxillary sinusitis with a history of odontogenic infection, dentoalveolar surgery, periodontal surgery, or in those resistant to conventional sinusitis therapy. Diagnosis usually requires a thorough dental and clinical evaluation including appropriate radiographs. The most common causes of odontogenic sinusitis include dental abscesses and periodontal disease that had perforated the Schneidarian membrane, irritation and secondary infection caused by intra-antral foreign bodies, and sinus perforations during tooth extraction. An odontogenic infection is a polymicrobial aerobic-anaerobic infection, with anaerobes outnumbering the aerobes. The most common isolates include anaerobic streptococci and gram-negative bacilli, and Enterobacteriaceae. Surgical and dental treatment of the odontogenic pathological conditions combined with medical therapy is indicated. When present, an odontogenic foreign body should be surgical removed. Surgical management of oroantral communication is indicated to reduce the likelihood of causing chronic sinus disease. The management of odontogenic sinusitis includes a 3- to 4-week course of antimicrobials effective against the oral flora pathogens.