Forty adult patients with Salmonella typhi and S. paratyphi infections were studied in a randomly assigned prospective study to receive norfloxacin (12 drug-sensitive and 8 drug-resistant cases) or chloramphenicol (20 cases). No complication occurred in either group and no side effect was noted in the norfloxacin-treated group. The results suggest that a 7 d course of twice daily norfloxacin promises to be an alternative to a 14 d course of chloramphenicol for treating chloramphenicol-sensitive and multidrug-resistant typhoid and paratyphoid fevers.