Atrophic rhinitis is a term used to describe a rare nasal infection. Although it does not have a fatal outcome, cause osteomyelitis, or produce pain, it does induce bilateral nasal obstruction and a persistent foul odor of which the subject and others are painfully aware. The organism most often associated with atrophic rhinitis is Klebsiella ozenae. Antibiotic susceptibility patterns of this microorganism have made treatment with orally administered antibiotics difficult. K ozenae was cultured from the nasal cavity of three patients. Two patients were treated for two weeks with tobramycin (MIC, 4 micrograms/ml; 4 mg/kg/day). Odor decreased in one patient, but K ozenae failed to clear. In the second patient both odor and K ozenae disappeared. The third patient was treated for 1 week with tobramycin (MIC, 4 micrograms/ml; 4 mg/kg/day); odor decreased, but K ozenae could still be cultured. She was treated for an additional 2 weeks with topical gentamicin (MIC, 0.5 micrograms/ml) with disappearance of both odor and K ozenae. Intravenous aminoglycoside may be helpful in treating atrophic rhinitis, but topical aminoglycoside may provide an effective and cheaper form of treatment.