A clinical trial was conducted in 50 patients with blood cultures positive for Salmonella typhi or Salmonella paratyphi to compare treatment with ciprofloxacin for seven days, 500 mg b.i.d. (Group 1, 25 patients), with treatment for ten days, 750 mg b.i.d. (Group 2, 25 patients). Clinical cure was defined as defervescence of fever by day 5 of treatment, with an absence of complications and no clinical relapse. The clinical cure rate was 84% for group 1 and 96% for group 2; the difference in these rates was not statistically significant. The blood cultures of all patients were sterile by day 2 of treatment and remained so until the sixth month of follow-up. It was concluded that ciprofloxacin treatment for ten days in enteric fever is not necessary. Further studies are needed to evaluate the efficacy of shortening the duration of antibiotic therapy.