Adult vaccination rates are well below national goals of 90%. We examined medical records of 810 adults > or =65 years to determine number and type of visits, discussion and patient refusals of vaccines, influenza vaccinations over three seasons, and pneumococcal and tetanus vaccinations over 5 years. From the medical record, immunization rates were 24.1% for annual influenza, 49.1% for pneumococcal polysaccharide and 28.6% for tetanus vaccine. During the 27 month study period, patients averaged 1.3 +/- 1.9 acute visits, 6.9 +/- 5.1 chronic visits and 0.48 +/- 0.91 preventive visits (mean +/- S.D.). Missed opportunities to vaccinate ranged from 38.4 to 94.5% of visits. Vaccination rates were higher if medical records included health maintenance flow sheets. Failure to discuss vaccination, to vaccinate at acute care visits, and low frequency of preventive visits resulted in missed opportunities to vaccinate. A health maintenance flow sheet can prompt providers to discuss vaccination and record vaccines as they are administered.