Immunization of adults has been deficient in the United States. According to interviews conducted during their visits to an emergency room, only 20.1% of 350 patients who fit into high-risk categories for immunization had heard of pneumococcal vaccine, whereas 82.7% had heard of influenza vaccine. Only 8.6% and 47.8%, respectively, had ever been given pneumococcal or influenza vaccine. Previous pneumococcal vaccination was six times more common (10.3% vs 1.6%) and prior influenza vaccination twice as common (52.7% vs 25.4%) in the respondents who could identify a primary care provider or clinic than in those who could not. Of the patients who had not received a specific vaccine, about 60% indicated that they would take pneumococcal or influenza vaccine if it was offered while they were in the emergency room setting. Offering vaccine in an emergency room setting promises to complement other approaches to immunizing adults at high risk for complications of influenza and pneumococcal infections.