Patients with rheumatoid arthritis (RA) have an increased risk of infection as a result of alterations in immune regulation, debility, and comorbid illnesses. TNF-alpha is of central importance in the pathophysiological responses to infection and inflammation, and plays a crucial role in host defence. Pneumocystis carinii is an opportunistic pathogen that commonly affects individuals with inadequate T-cell mediated immune response. Patients with acquired immune deficiency, as well as those receiving immunosuppressive drugs for various conditions have an increased risk of P. carinii pneumonia (PCP). We report the development of PCP in a woman with RA shortly after the initiation of anti-TNF-alpha treatment with adalimumab.