Ofloxacin was administered to 18 patients and ciprofloxacin to 17 patients suffering from acute or chronic complicated urinary tract infections. Patients received doses of 100 mg ofloxacin, b.i.d., or 250 mg ciprofloxacin, b.i.d., for seven days. The clinical and bacteriological response were evaluated after 17 days. Resolution of symptoms were found in approximately 60% of cases for both treatments and bacteriological eradication was 66% for ofloxacin and 50% for ciprofloxacin. Side-effects such as itching and rash were reported in three cases. The results indicate that ofloxacin and ciprofloxacin are safe and effective agents in the treatment of complicated urinary tract infections.