A novel Pseudomonas species, for which the name Pseudomonas otitidis sp. nov. is proposed, was identified from clinical specimens of infected human ears. Forty-one pseudomonads (34 from patients with acute otitis externa, six from patients with acute otitis media with otorrhoea and one from a patient with chronic suppurative otitis media) were recovered that did not match any known species. On the basis of genetic analyses and biochemical characterization, these isolates were shown to belong to the genus Pseudomonas. 16S rRNA gene sequence analysis and DNA-DNA hybridization studies indicated that this novel bacterium is closely related to, but different from, Pseudomonas aeruginosa. A description of this species is based on polyphasic studies of 11 clinical isolates. The type strain of Pseudomonas otitidis is MCC10330T (=ATCC BAA-1130T = DSM 17224T).