In this study, we present population-based data regarding the prevalence of aerococci in clinical urinary samples. During a 3-month period, all aerococcal isolates from urinary samples from 2 clinical microbiology laboratories were collected. We identified 64 Aerococcus urinae isolates and 40 Aerococcus sanguinicola isolates, which correlates with an incidence of 33 cases of aerococcal bacteriuria per 100,000 inhabitants per year. The median age was 83years for all patients with aerococcal bacteriuria, which was significantly higher than for patients with Escherichia coli or Enterococcus faecalis bacteriuria. Sex was almost equally distributed between men and women with aerococcal bacteriuria, whereas females dominated in E. coli bacteriuria. The aerococcal isolates displayed low MICs for ampicillin, cefalotin, mecillinam, and nitrofurantoin. Most A. sanguinicola isolates were resistant to ciprofloxacin, whereas most A. urinae isolates had low MICs. Clinical studies are needed to establish clinical breakpoints and optimal treatment.