Background: Influenza vaccination coverage remains unacceptably low among persons aged ≥65 years and younger high-risk adults. This study assessed locations at which US adults receive influenza (flu) vaccinations and the relative roles that traditional and nontraditional vaccination settings play in influenza vaccine delivery. Methods: We analyzed data on types of settings at which last flu shot was received, reported by adult respondents to the 1999 Behavioral Risk Factor Surveillance System, stratified by age group and medical condition. We used multivariable logistic regression to identify factors associated with nontraditional vaccination settings. Results: In 1998-1999, reported influenza vaccination coverage was 19% for persons aged 18-49 years, 36% for persons aged 50-64 years, and 67% for persons aged ≥65 years. Seventy percent of flu shots received by persons aged ≥18 years were reportedly administered in doctors' offices and other traditional settings. Vaccination in nontraditional settings (eg, workplace, stores, community centers) was more likely for young, healthy, employed, white, college-educated adults who had not had a recent routine checkup. Conclusion: Physicians should offer vaccination services at every opportunity. Increasing access to vaccination services in nontraditional settings should be considered as another strategy in pursuit of national vaccination coverage objectives.