OBJECTIVE: To assess if a short course of antibiotics starting at the time of the removing a short-term urethral catheter decreases the incidence of subsequent urinary tract infection (UTI). PATIENTS AND METHODS: Patients across specialities with a urethral catheter in situ for >/= 48 h and </= 7 days were recruited at the time of catheter removal. Patients were excluded if they had had recent genitourinary surgery or were on antibiotics. Eligible patients were randomly assigned to a 48-h course of either ciprofloxacin or placebo tablets starting 2 h before catheter removal. A catheter specimen of urine was obtained before the start of the trial medication. The follow-up was at 7 and 14 days after catheter removal, with a questionnaire for UTI symptoms, and a mid-stream urine sample was taken. RESULTS: Forty-eight patients were recruited and had a complete follow-up (25 received ciprofloxacin and 23 placebo). Of the ciprofloxacin group, four patients (16%) had a UTI at the follow-up after catheter removal, and two were symptomatic. The UTI in two patients (including one of those symptomatic) was newly developed after catheter removal; the other two UTIs were a result of failure to resolve a catheter-associated UTI. All these UTIs in the ciprofloxacin group were resistant to ciprofloxacin. Of the placebo group, three patients (13%) had a UTI at the follow-up after removal, and one patient was symptomatic. The UTI, newly developed after catheter removal, was resistant to ciprofloxacin. The other two patients were asymptomatic; their UTIs were a result of failure to resolve a catheter-associated UTI, and one was resistant to ciprofloxacin. CONCLUSIONS: The risk of UTI (both symptomatic and asymptomatic) after removing a urethral catheter is real, even in absence of catheter-associated UTI before removal. UTIs occurring after removing a short-term urinary catheter had a high rate of resistance to ciprofloxacin. There was no detectable significant benefit in using prophylactic ciprofloxacin to reduce the UTI rate after catheter removal.