To determine the incidence and risk factors related to isolation of Pseudomonas aeruginosa or Enterococcus spp from urine cultures obtained from patients in the emergency department (ED), a 1-year prospective study was conducted of all urine specimens collected in the ED of a general hospital. Specimens from which one of these organisms was isolated at a concentration of ≥105 cfu/ml were included. Of 744 positive urine cultures, 39 (5%) were P. aeruginosa and 28 (4%) Enterococcus spp. Comparison with a control cohort of 80 patients with Escherichia coli bacteriuria revealed several univariate indicators for P. aeruginosa bacteriuria, including male sex, indwelling catheter, past prostatectomy, hospitalization in the previous 2 months and pregnancy; multivariate indicators were indwelling catheter (p<0.001) and male sex (p<0.001). Enterococcus and P. aeruginosa were significantly more often associated with asymptomatic bacteriuria. These data will help clinicians select appropriate antibiotic treatment for patients with urinary tract infections.