Atrophic rhinitis is a chronic inflammatory disease characterized by progressive atrophy of nasal mucosa. Cedecea davisae, a rare pathogen, is a new member of Enterobacteriaceae family. In this article, we report a patient with atrophic rhinitis whose culture test revealed Cedecea davisae. The patient was operated due to accompanying posterior ethmoid mucocele. Levofloxacin and nasal irrigation were administered for two months. Significant improvement was observed in patient's complaints and nasal signs at postoperative sixth month. In conclusion, Cedecea davisae has been thought to cause atrophic rhinitis and mucocele in this patient. Patient recovered with simple treatment. These bacteria should be kept in mind as a causative agent for atrophic rhinitis.