Fifty-eight patients with human immunodeficiency virus infection were analyzed for clinical manifestations and potential risk factors for Pseudomonas aeruginosa infection by use of case-control methodology. Most had AIDS. Of 73 episodes of P. aeruginosa infection, 45 (62%) were bacteremias primarily associated with central venous catheters (16), pneumonia (12), soft tissue (4), or urinary tract infections (4). Twenty-eight episodes (38%) were nonbacteremic, with pneumonia (13), soft tissue infections (6), and sinusitis (4) accounting for the majority of infections. Fifty episodes (68%) were community-acquired. The recurrence rate was 23%. The overall mortality attributable to P. aeruginosa infection was 22%. Central venous and urinary catheter use and steroid therapy were significantly more frequent in cases than controls (P < .05). Thus, P. aeruginosa infection in patients with advanced human immunodeficiency virus disease is often community-acquired and associated with substantial mortality and, in some cases, specific risk factors.