In the literature there are three comparative and two open studies in which 1,395 patients received 3 g of fosfomycin trometamol per os 12 or three hours before and 24 hours after surgery: 625 patients received control substances or placebo. In the comparative studies the incidence of postoperative bacteriuria in patients treated with fosfomycin trometamol ranged from 2.9 to 7.6% at one week and from 1.2 to 3.2% at two to four weeks follow-up, and was lower than in patients treated with reference drugs or placebo. In the open study, postoperative bacteriuria ranged from 2.9 to 6.0% at one week follow-up. In our open study, 70 patients were evaluable. Four out of 70 (5.7%) developed fever > or = 38 degrees C, with positive urine culture, during the first three postoperative days. At two weeks follow-up another 5.7% showed a symptomatic urinary tract infection with a cumulative infection rate of 11.4%. In all cases, the bacteria were resistant to fosfomycin trometamol. A low incidence, 4.2%, of side effects, mainly related to the gastrointestinal tract, was observed. Fosfomycin trometamol proved to be effective with the advantage of no risk of cross resistance, practical pharmaceutical formulation with good patient compliance, good safety profile with few side effects and a satisfactory cost/benefit ratio.