We describe a patient who presented with a massive chest-wall abscess after a severe debilitating illness that lasted 3 months. Steroid therapy, administered for 4 weeks, masked the slow development of an extensive axillary and chest-wall abscess. After multiple negative tests, the patient's prolonged illness was diagnosed as cat-scratch disease (CSD). An indirect fluorescent antibody test revealed that two convalescent serum samples were positive for IgG to Bartonella clarridgeiae, but no other Bartonella species. We also review 12 cases of severe chest and pulmonary disease due to CSD that were reported in the English-language literature. Thoracopulmonary findings associated with CSD, pathogenic mechanisms of bartonella infections, diagnostic criteria, and management of CSD are presented.