A 60-year-old heterosexual man with AIDS was admitted to hospital with dyspnea, a severe paroxysmal non-productive cough of two months' duration, low-grade fever and exhaustion. Bordetella pertussis was cultured from a bronchoalveolar lavage specimen. After erythromycin therapy (500 mg q.i.d. for two weeks) all respiratory symptoms resolved progressively over a four-week period. Bordetella pertussis should be added to the long list of pathogens that may cause respiratory disease in persons with HIV infection.