The primary care physician is faced with a bewildering array of new oral antimicrobials to treat common infections. These agents promise to be extremely effective as replacements for time-honored drugs, as prophylaxis, and for the treatment of infections previously requiring prolonged intravenous therapy. The overuse of the newer macrolides, quinolones, and beta-lactam beta-lactamase inhibitors may prove to be ecologically and economically costly. It is feared that the selective pressure from these broad spectrum agents may burden society with an even greater problem of multiply resistant community-acquired pathogens. The specific therapeutic and economic advantages and disadvantages of each class should be considered and the decision to employ these agents should be highly individualized.