The antimicrobial resistance profiles, comprising 12 antibiotics, of 2478 isolates of Escherichia coli from the ECO.SENS Project involving women with acute uncomplicated urinary tract infection at 252 community health care centres in 17 countries were determined. Resistance to ampicillin alone (6.3%) and sulfamethoxazole alone (5.4%) were the most common 'single resistances'. Multiple resistance was most common in Spain and least common in Finland. The main associated-resistance profiles involved ampicillin/sulfamethoxazole (8.7%) and ampicillin/sulfamethoxazole/trimethoprim/trimethoprim-sulfamethoxazole (6.4%). The most common profile of multiple resistance was ampicillin/sulfamethoxazole/trimethoprim/trimethoprim-sulfamethoxazole/nalidixic acid/ciprofloxacin. Twenty-one isolates, half of which came from Spain, were resistant to seven antibiotics or more. Three isolates, one from Spain and two from Portugal, were resistant to nine of the 12 antibiotics investigated.