Despite the burden of disease caused by pneumococcus, adult immunization rates are modest. To understand barriers in diverse settings, we surveyed patients age > or =66 years at: (1) inner-city health centers; (2) Veterans Affairs (VA) outpatient clinics; (3) rural practices; and (4) suburban practices. Among the 1007 respondents, self-reported pneumococcal vaccination rates were: 85% VA; 62% rural; 66% suburban; and 57% inner-city with substantial variability among practices. Half of the unvaccinated (50%) did not know they needed vaccination. Most vaccinees (90%) thought that their doctor believed they should be vaccinated, compared with 23% of the unvaccinated (P<0.0001). More of the vaccinees (75%) believed that the vaccine "keeps a person from getting pneumonia" than the unvaccinated (54%; P=0.0001). In regression analysis, predictors of vaccination included: belief that doctor recommends vaccine, feeling that vaccination is wise, recommendation by someone in the physician's office, and receipt of influenza vaccine.