The deployment of the electronic medical record (EMR) is widely seen by healthcare policy makers and service managers as a key step in the achievement of more efficient and integrated healthcare services. However, our studies of medical work practices reveal important discrepancies between the presumptions of EMR and the ways in which healthcare professionals actually use and communicate information. These lead us to conclude it may be some time before technologies like the EMR can deliver promised benefits, and will do so only if they are allowed to evolve via user-led design and development processes.