The Emergency Department is a challenging environment to implement a sustainable pneumococcal vaccination program. To increase vaccination rates for patients > or = 65 years old, we prospectively evaluated a closed-loop informatics approach over a 1-year period. Among 3,455 screened patients 1,393 were up-to-date and 2,062 were eligible for the vaccination. 159 (7.7%) patients received the vaccine at the initial visit and an additional 59 (2.9%) at a subsequent visit, resulting in an overall rate increase of 10.6%.