Chloramphenicol is still very effective for acute enteric fever. A literature survey does not confirm the repeated claims of decreasing efficacy over the past 20 years (not taking into account the R factor mediated resistance noted since 1972/73). However, there have been regional variations in the time needed to achieve defervescence under chloramphenicol treatment since the early 1950s. When comparing alternative antimicrobials with chloramphenicol other criteria apart from clinical efficacy have to be considered, namely, influence on the rate of excretion of the organisms and the relapse rate, ease of administration parenterally, toxicity, cost, and the possible occurrence of resistance to Salmonella typhi or S. paratyphi A/B.