Electronic medical records (EMRs) are generally perceived to improve patient safety, and prior reviews have found that EMR implementation is associated with improvement in some measures of safety and quality. This study of EMR implementation in a large primary care medical group found a positive association between implementation of a new EMR and safety culture, with sustained improvement in Safety Attitudes Questionnaire scores over a 3-year period following implementation. Interestingly, the perceived improvement in safety culture was smallest in the first year of use of the new EMR; a prior study found that 1 year of experience was necessary before primary care physicians felt a new EMR improved safety and quality.