The efficacy and safety of fleroxacin and ciprofloxacin were evaluated in a single-centre, prospective, randomised, blinded study of patients with complicated urinary infection in a spinal injury unit. Patients were randomised to receive oral fleroxacin 400 mg once daily (n = 68) or oral ciprofloxacin 500 mg twice daily (n = 65) for 10 days. Clinical cure assessed 5-9 days after therapy was obtained in 41 of 42 (98%) assessable patients in the fleroxacin group, and in 41 of 43 (95%) of the ciprofloxacin group, and was maintained at the 6-week follow-up visit in all but 1 patient in each group. Bacteriological eradication rates 5-9 days after therapy exceeded 88% in the fleroxacin group and 86% in the ciprofloxacin group, and 69 and 65%, respectively, 6 weeks after completion of therapy. Adverse events occurred in a similarly low percentage of patients (19 and 20%) in both treatment groups, and consisted primarily of nausea. Once daily fleroxacin appears to be as safe and effective as twice daily ciprofloxacin and both represent efficacious treatment in complicated urinary infection in spinal injury patients.