Urinary infections are caused mainly by Escherichia coli (E. coli); indiscriminate use of antibiotics has caused an increase in infections due to extended-spectrum beta-lactamase (ESBL)-producing strains. Aiming to determine the sensitivity to fosfomycin, a study was conducted in ESBL-producing E. coli strains isolated from urine cultures at a hospital in Peru. Two hundred and sixty-six (266) strains of E. coli were collected, which were determined by conventional methods to be ESBL-producing. Sensitivity to fosfomycin was determined through minimum inhibitory concentration with the agar dilution method and the diffusion disc method. One hundred and ninety-two (192) (72.2%) strains of ESBL-producing E. coli strains sensitive to Fosfomycin were found. It, therefore, follows that fosfomycin exhibits antimicrobial activity against ESBL-producing E. coli strains and that it could be considered a good treatment option for resistant strains.