Electronic medical record-based test results management interventions hold the potential to reduce errors in the test result follow-up process. However, ensuring the adaptability of such systems to the clinical environment has proven challenging. The aim of this study was to explore how contextual factors can influence senior emergency physicians' experience and perceived impacts of an electronic result acknowledgement system across two Emergency Departments. Semi-structured, in-depth interviews relating to physician test result acknowledgement processes before and after system implementation were conducted with 14 senior Emergency Physicians across two Australian metropolitan teaching hospitals. Perceived impacts of the electronic test result acknowledgement system on test result endorsement varied in terms of: changes to workflow, impacts on patient safety; and changes to documentation practices. Existing work practices and the departmental staffing mix and roles play a part in determining the nature of change that an electronic result acknowledgement system is likely to produce.