Influenza and related pneumonia continue to cause significant amounts of morbidity and mortality despite the availability of effective vaccines. Two comparable counties in Massachusetts served as project areas of a national trial to see if reimbursement for immunizing Medicare-B eligible recipients against influenza would increase the use of the vaccine and reduce the costs attributed to related morbidity. Providers of health and social services to elders were recruited to participate in one county. A variety of professional and public education campaigns and media were used to promote influenza immunizations. Laboratory-based surveillance was instituted in both counties to assess the extent of circulating virus in each. Vaccine was made available to medical providers in both counties. While the amount of vaccine used in the comparison county increased by 6% from pre-project time (16,000 to 17,000 doses administered), vaccine use increased 219% in the intervention county (21,250 to 46,494 doses administered). In a post-project survey of participating physicians, 88% of 238 respondents reported administering less than 100 doses of influenza vaccine per year prior to the project. By the end of the project, only 32% administered less than 100 in the previous year. This project demonstrated the need for educating both the provider and the public in order to successfully promote immunizations. It was not clear, however, if reimbursement was a more important factor for promoting influenza immunizations than was universal distribution of free vaccine.