Abacteriological examination of the maxiUary sinus and nasal cavity was conducted in 93 patients with chronic sinusitis. A bacteriological examination of the larynx was also carried out in those patients who had pus retention on the surface of the arytenoid region of the larynx. The results from these examinations were compared to each other. Staphylococcus epidermidis was frequently detected from the maxillary sinus and the nasal cavity. Various kinds of bacteria were detected from the larynx, which suggested that the sputum had mixed flora. The species of bacteria from the maxillary sinus were coincident with those from the nasal cavity at a rate of approximately 69.2%. When the chronic sinusitis was due to anaerobic bacteria, however, it was diiificult to isolate the causative bacteria from the nasal cavity. The coincidence rate between bacteria from the nasal cavity and those from the larynx was 31.4%. It was presumed that postnasal drip had some effect on the laryngeal pus.