Fosfomycin tromethamine (FT) is effective in vitro in extended spectrum beta-lactamase (ESBL)-producing Escherichia coli strains. The aim of this study was to evaluate the effect of FT in the treatment of ESBL-producing E. coli-related lower urinary tract infection. All patients were aged >18; had dysuria or problems with frequency or urgency in passing urine; had >20leukocytes/mm(3) in urine sediment and an ESBL-producing E. coli urine culture (>10(5)cfu/mm(3)); no leukocytosis or fever; and were treated with FT between September 2004 and July 2006 in our outpatient clinic and hospital. ESBL detection was performed by double disk synergy tests. All patients had received FT (3gx1 every other night, three times) and had a control urine culture taken 7 to 9 days after this therapy. Clinical success was defined as resolution of symptoms on the control visit; microbiological success was defined as a sterile control urine culture. In all, 52 patients (aged 55.0+/-18.3, range 19-85; 25 males, 27 females) were included in the study. Overall clinical and microbiological success was 94.3% (49/52) and 78.5% (41/52), respectively. Although it is not a randomized controlled study, these data show that FT may be a suitable, effective and cheap alternative in the treatment of ESBL-producing E. coli-related lower urinary tract infection.