An increasing number of clinical studies have been reported in which neutropenia has been identified as an important independent risk factor in the development of infectious complications in patients with HIV and AIDS. Information on the clinical significance of infecting pathogens and the causes of neutropenia within different patient groups will be discussed, and may have clinical implications in subsequent disease management in these groups. Although the use of highly active antiretroviral therapy has shown some promise in the treatment of HIV-associated hematologic disturbances and immune dysfunction, the rate of virological failure with this treatment over time suggests that these disturbances could reappear in the near future, as well as their associated infectious complications.