Objectives: To understand the potential roles of various patient and provider factors in the underuse of pneumococcal vaccination in Medicare-eligible older African Americans. Design: The Cardiovascular Health Study. Setting: Four U.S. states. Participants: Seven hundred ninety-five pairs of community-dwelling Medicare-eligible African-American and white adults aged 65 and older, balanced according to age and sex. Measurements: Data on self-reported race, receipt of pneumococcal vaccination, and other important sociodemographic and clinical variables were collected at baseline. Results: Participants had a mean age Â± standard deviation of 73 Â± 6; 63% were female. Pneumococcal vaccination rates were 22% for African Americans and 28% for whites (unadjusted odds ratios (OR) for African Americans=0.75; 95% confidence interval (CI)=0.60-0.94; P=.01). This association remained significant despite adjustment for sociodemographic and clinical confounders, including education, income, chronic obstructive pulmonary disease, and prior pneumonia (OR=0.74, 95% CI=0.56-0.97; P=.03), but the association was no longer significant after additional adjustment for the receipt of influenza vaccination (OR=0.79, 95% CI=0.59-1.06; P=.12). Receipt of influenza vaccination was associated with higher odds of receiving pneumococcal vaccination (unadjusted OR=6.43, 95% CI=5.00-8.28; P<.001), and the association between race and pneumococcal vaccination lost significance when adjusted for influenza vaccination alone (OR=0.81, 95% CI=0.63-1.03; P=.09). Conclusion: The strong association between receipt of influenza and pneumococcal vaccinations suggests that patient and provider attitudes toward vaccination, rather than traditional confounders such as education and income, may help explain the underuse of pneumococcal vaccination in older African Americans. © 2010, The American Geriatrics Society.