In Taiwan, pertussis is a notifiable disease with a low incidence in recent years, and antimicrobial susceptibility testing for the causative agent, Bordetella pertussis, has not been reported to date. In May 2007, the Centers for Disease Control, Taiwan, was informed of a 1-month-old pertussis patient who did not respond to erythromycin treatment. In this study, we report the result of antimicrobial susceptibility testing performed for the suspected erythromycin-resistant isolate, as well as for an additional 27 B. pertussis clinical isolates that represented almost all epidemiologically unrelated isolates obtained throughout Taiwan between 2003 and 2007. All isolates were fully susceptible to azithromycin, erythromycin, clarithromycin and trimethoprim/sulfamethoxazole (MIC ⋜0.047 μg ml−1). This result demonstrates the general susceptibility of B. pertussis to antimicrobial agents in vitro in Taiwan.