During a five-week period, Pseudomonas paucimobilis was isolated from maxillary sinus irrigation washes of four patients who attended an ear, nose and throat clinic. The saline irrigation solution was found to be contaminated with the same organism. Further investigation demonstrated the organism in a majority of hospital sinks surveyed. Although P. paucimobilis was isolated from clinical specimens, the presence of the organism did not appear to have clinical significance.