Age-related variations in care have been identified for HIV-associated Pneumocystis carinii pneumonia (PCP) in both the 1980s and 1990s. We evaluated if age-related variations affected all aspects of HIV-specific and non-HIV-specific care for HIV-infected individuals with PCP or community-acquired pneumonia (CAP), or whether age-related variations were primarily limited to HIV-specific aspects of care. Subjects were HIV-infected persons with PCP (n = 1855) or CAP (n = 1415) hospitalized in 8 cities from 1995 to 1997. Nine percent of our study patients had received protease inhibitors and 39% had received any type of antiretroviral therapy prior to hospitalization. Data were abstracted from medical records and included severity of illness, HIV-specific aspects of care (initiation of PCP medications), general measures of care [initiation of CAP medications, intubation, and intensive care units (ICU)], and inpatient mortality. Compared to younger patients, pneumonia patients 50 years of age or older were significantly more likely to: be severely ill (PCP, 20.4% vs. 10.4%; CAP, 27.5% vs. 14.9%; each p = 0.001), receive ICU care (PCP, 22.0% vs. 12.8%, p = 0.002; CAP: 15.1% vs. 9.4%; p = 0.02), and be intubated (PCP, 14.6% vs. 8.4%, p = 0.01; CAP, 9.9% vs. 5.6%, p = 0.03). Compared to younger patients, older patients (>/=50 years) had similar rates of timely medications for CAP (48.5% vs. 50.8%) but had lower rates of receiving anti-PCP medications (85.8% vs. 92.9%, p = 0.002). Differences by age in timely initiation of PCP medications, ICU use, and intubation were limited to the nonseverely ill patients. Older hospitalized patients were more likely to die (PCP, 18.3% vs. 10.4%; CAP, 13.4% vs. 8.5%; each p < 0.05). After adjustment for disease severity and timeliness of antibiotic use, mortality rates were similar for both age groups. Physicians should develop strategies that increase awareness of the possibility of HIV infection in older individuals.