The aim of this study was to evaluate the effect of nitrofurantoin (NFT) in the treatment of extended-spectrum beta-lactamase (ESBL)-producing Escherichia coli-related lower urinary tract infection (LUTI). The hospital records of all patients aged >18 years with dysuria or problems with frequency or urgency in passing urine, >20 leukocytes/mm(3) in urine microscopy and culture-proven ESBL-producing NFT-sensitive E. coli in the urine (>10(5) CFU/mm(3)), no leukocytosis or fever and who were treated with NFT between January 2006 and May 2011 in our outpatient clinic or in the hospital were evaluated. All patients had received a NFT 50 mg capsule every 6 h for 14 days and had a control urine culture taken 7-9 days after therapy. Clinical success was defined as resolution of symptoms at the control visit, and microbiological success was defined as a sterile control urine culture. A total of 75 patients (mean +/- standard deviation age, 54 +/- 17 years; 45 females, 30 males, all but 14 with complicated LUTI) fulfilled the study inclusion criteria. Overall clinical and microbiological success rates were 69% (52/75) and 68% (51/75), respectively. Control urine culture performed 28-31 days after the end of therapy was available in 31/51 patients (61%) with microbiological success. Re-infection and relapse rates were 6.5% (2/31) and 3.2% (1/31), respectively. In conclusion, these results suggest that NFT may be an alternative in the treatment of ESBL-producing E. coli-related LUTI. This is the first study in which NFT was used in the treatment of LUTI due to ESBL-producing E. coli as well as in patients with complicated UTI. (C) 2012 Elsevier B. V. and the International Society of Chemotherapy. All rights reserved.