Aim To investigate whether diabetes mellitus is a risk factor for resistance in Escherichia coli isolated from patients with bacteriuria. Methods Data were obtained from a multicentre study. A clean-voided midstream urine culture was collected from 636 women with diabetes, who were between 18 and 75-years-old, attended an out-patient department and had no symptoms of a urinary tract infection. The resistance of E. coli was determined for different antimicrobials. The results were compared with resistance data from routine isolates of E. coli, obtained from women in the same age category, time period and location. Results A total of 135 E. coli were isolated from women with diabetes mellitus (mean age 57 ± 14 years) and compared with 5907 routine isolates of E. coli obtained from female patients visiting an out-patient department (mean age 52 ± 17 years). The resistance rates of E. coli isolated from diabetic patients and the routine isolates of E. coli to trimethoprim-sulfamethoxazole were 19% and 23%, respectively, to amoxicillin 16% and 32%, to nitrofurantoin 1% and 3%, to ciprofloxacin 0% and 4%, to ofloxacin 0% and 5%, and to norfloxacin 1% and 4%. Conclusion The resistance of uropathogenic E. coli in non-hospitalized women with diabetes mellitus is not higher than that seen in routine isolates of E. coli. This suggests that diabetes in itself is not a risk factor for resistance.