Data from surveillance studies show increasing prevalence of respiratory pathogens resistant to commonly used antibiotics. Over the past years, clarithromycin in the treatment of community-acquired pneumonia (CAP) have shown consistent rates of clinical cure and bacteriological eradication similar to those observed with comparator agents. The incidence of clarithromycin treatment failure in patients infected with S. pneumoniae is substantially less than that predicted by macrolide resistance rates from surveillance programs. In summary, despite widespread use since its introduction, clarithromycin remains active both in vitro and in vivo against clinically relevant respiratory tract pathogens.