Individuals with human immunodeficiency virus (HIV) infection are more susceptible to bacterial infections because of defects in both cellular and humoral immunity. The most common causes of community-acquired pyogenic bacterial pneumonia in HIV-infected patients are Streptococcus pneumoniae and Haemophilus influenzae. The clinical presentation of HIV-infected patients with pyogenic pneumonia does not seem to differ significantly from that of patients without HIV infection. Response to therapy is generally good, and complications relatively few. Prevention of bacterial pneumonia is very important in the care of HIV-infected persons. The pneumococcal vaccine is currently recommended for all HIV-seropositive individuals, although its efficacy is unknown is this setting. Other forms of prevention require further investigation but may prove to be helpful.